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53427 Commits

Author SHA1 Message Date
Christian Brauner
0e020c19bb BACKPORT: clone: add CLONE_PIDFD
This patchset makes it possible to retrieve pid file descriptors at
process creation time by introducing the new flag CLONE_PIDFD to the
clone() system call.  Linus originally suggested to implement this as a
new flag to clone() instead of making it a separate system call.  As
spotted by Linus, there is exactly one bit for clone() left.

CLONE_PIDFD creates file descriptors based on the anonymous inode
implementation in the kernel that will also be used to implement the new
mount api.  They serve as a simple opaque handle on pids.  Logically,
this makes it possible to interpret a pidfd differently, narrowing or
widening the scope of various operations (e.g. signal sending).  Thus, a
pidfd cannot just refer to a tgid, but also a tid, or in theory - given
appropriate flag arguments in relevant syscalls - a process group or
session. A pidfd does not represent a privilege.  This does not imply it
cannot ever be that way but for now this is not the case.

A pidfd comes with additional information in fdinfo if the kernel supports
procfs.  The fdinfo file contains the pid of the process in the callers
pid namespace in the same format as the procfs status file, i.e. "Pid:\t%d".

As suggested by Oleg, with CLONE_PIDFD the pidfd is returned in the
parent_tidptr argument of clone.  This has the advantage that we can
give back the associated pid and the pidfd at the same time.

To remove worries about missing metadata access this patchset comes with
a sample program that illustrates how a combination of CLONE_PIDFD, and
pidfd_send_signal() can be used to gain race-free access to process
metadata through /proc/<pid>.  The sample program can easily be
translated into a helper that would be suitable for inclusion in libc so
that users don't have to worry about writing it themselves.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <christian@brauner.io>
Co-developed-by: Jann Horn <jannh@google.com>
Signed-off-by: Jann Horn <jannh@google.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: David Howells <dhowells@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Aleksa Sarai <cyphar@cyphar.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>

(cherry picked from commit b3e5838252665ee4cfa76b82bdf1198dca81e5be)

Conflicts:
        kernel/fork.c

(1. Replaced proc_pid_ns() with its direct implementation.)

Bug: 135608568
Test: test program using syscall(__NR_sys_pidfd_open,..) and poll()
Change-Id: I3c804a92faea686e5bf7f99df893fe3a5d87ddf7
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-03 13:44:48 -07:00
Christian Brauner
cf9f829523 BACKPORT: signal: add pidfd_send_signal() syscall
The kill() syscall operates on process identifiers (pid). After a process
has exited its pid can be reused by another process. If a caller sends a
signal to a reused pid it will end up signaling the wrong process. This
issue has often surfaced and there has been a push to address this problem [1].

This patch uses file descriptors (fd) from proc/<pid> as stable handles on
struct pid. Even if a pid is recycled the handle will not change. The fd
can be used to send signals to the process it refers to.
Thus, the new syscall pidfd_send_signal() is introduced to solve this
problem. Instead of pids it operates on process fds (pidfd).

/* prototype and argument /*
long pidfd_send_signal(int pidfd, int sig, siginfo_t *info, unsigned int flags);

/* syscall number 424 */
The syscall number was chosen to be 424 to align with Arnd's rework in his
y2038 to minimize merge conflicts (cf. [25]).

In addition to the pidfd and signal argument it takes an additional
siginfo_t and flags argument. If the siginfo_t argument is NULL then
pidfd_send_signal() is equivalent to kill(<positive-pid>, <signal>). If it
is not NULL pidfd_send_signal() is equivalent to rt_sigqueueinfo().
The flags argument is added to allow for future extensions of this syscall.
It currently needs to be passed as 0. Failing to do so will cause EINVAL.

/* pidfd_send_signal() replaces multiple pid-based syscalls */
The pidfd_send_signal() syscall currently takes on the job of
rt_sigqueueinfo(2) and parts of the functionality of kill(2), Namely, when a
positive pid is passed to kill(2). It will however be possible to also
replace tgkill(2) and rt_tgsigqueueinfo(2) if this syscall is extended.

/* sending signals to threads (tid) and process groups (pgid) */
Specifically, the pidfd_send_signal() syscall does currently not operate on
process groups or threads. This is left for future extensions.
In order to extend the syscall to allow sending signal to threads and
process groups appropriately named flags (e.g. PIDFD_TYPE_PGID, and
PIDFD_TYPE_TID) should be added. This implies that the flags argument will
determine what is signaled and not the file descriptor itself. Put in other
words, grouping in this api is a property of the flags argument not a
property of the file descriptor (cf. [13]). Clarification for this has been
requested by Eric (cf. [19]).
When appropriate extensions through the flags argument are added then
pidfd_send_signal() can additionally replace the part of kill(2) which
operates on process groups as well as the tgkill(2) and
rt_tgsigqueueinfo(2) syscalls.
How such an extension could be implemented has been very roughly sketched
in [14], [15], and [16]. However, this should not be taken as a commitment
to a particular implementation. There might be better ways to do it.
Right now this is intentionally left out to keep this patchset as simple as
possible (cf. [4]).

/* naming */
The syscall had various names throughout iterations of this patchset:
- procfd_signal()
- procfd_send_signal()
- taskfd_send_signal()
In the last round of reviews it was pointed out that given that if the
flags argument decides the scope of the signal instead of different types
of fds it might make sense to either settle for "procfd_" or "pidfd_" as
prefix. The community was willing to accept either (cf. [17] and [18]).
Given that one developer expressed strong preference for the "pidfd_"
prefix (cf. [13]) and with other developers less opinionated about the name
we should settle for "pidfd_" to avoid further bikeshedding.

The  "_send_signal" suffix was chosen to reflect the fact that the syscall
takes on the job of multiple syscalls. It is therefore intentional that the
name is not reminiscent of neither kill(2) nor rt_sigqueueinfo(2). Not the
fomer because it might imply that pidfd_send_signal() is a replacement for
kill(2), and not the latter because it is a hassle to remember the correct
spelling - especially for non-native speakers - and because it is not
descriptive enough of what the syscall actually does. The name
"pidfd_send_signal" makes it very clear that its job is to send signals.

/* zombies */
Zombies can be signaled just as any other process. No special error will be
reported since a zombie state is an unreliable state (cf. [3]). However,
this can be added as an extension through the @flags argument if the need
ever arises.

/* cross-namespace signals */
The patch currently enforces that the signaler and signalee either are in
the same pid namespace or that the signaler's pid namespace is an ancestor
of the signalee's pid namespace. This is done for the sake of simplicity
and because it is unclear to what values certain members of struct
siginfo_t would need to be set to (cf. [5], [6]).

/* compat syscalls */
It became clear that we would like to avoid adding compat syscalls
(cf. [7]).  The compat syscall handling is now done in kernel/signal.c
itself by adding __copy_siginfo_from_user_generic() which lets us avoid
compat syscalls (cf. [8]). It should be noted that the addition of
__copy_siginfo_from_user_any() is caused by a bug in the original
implementation of rt_sigqueueinfo(2) (cf. 12).
With upcoming rework for syscall handling things might improve
significantly (cf. [11]) and __copy_siginfo_from_user_any() will not gain
any additional callers.

/* testing */
This patch was tested on x64 and x86.

/* userspace usage */
An asciinema recording for the basic functionality can be found under [9].
With this patch a process can be killed via:

 #define _GNU_SOURCE
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <unistd.h>

 static inline int do_pidfd_send_signal(int pidfd, int sig, siginfo_t *info,
                                         unsigned int flags)
 {
 #ifdef __NR_pidfd_send_signal
         return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags);
 #else
         return -ENOSYS;
 #endif
 }

 int main(int argc, char *argv[])
 {
         int fd, ret, saved_errno, sig;

         if (argc < 3)
                 exit(EXIT_FAILURE);

         fd = open(argv[1], O_DIRECTORY | O_CLOEXEC);
         if (fd < 0) {
                 printf("%s - Failed to open \"%s\"\n", strerror(errno), argv[1]);
                 exit(EXIT_FAILURE);
         }

         sig = atoi(argv[2]);

         printf("Sending signal %d to process %s\n", sig, argv[1]);
         ret = do_pidfd_send_signal(fd, sig, NULL, 0);

         saved_errno = errno;
         close(fd);
         errno = saved_errno;

         if (ret < 0) {
                 printf("%s - Failed to send signal %d to process %s\n",
                        strerror(errno), sig, argv[1]);
                 exit(EXIT_FAILURE);
         }

         exit(EXIT_SUCCESS);
 }

/* Q&A
 * Given that it seems the same questions get asked again by people who are
 * late to the party it makes sense to add a Q&A section to the commit
 * message so it's hopefully easier to avoid duplicate threads.
 *
 * For the sake of progress please consider these arguments settled unless
 * there is a new point that desperately needs to be addressed. Please make
 * sure to check the links to the threads in this commit message whether
 * this has not already been covered.
 */
Q-01: (Florian Weimer [20], Andrew Morton [21])
      What happens when the target process has exited?
A-01: Sending the signal will fail with ESRCH (cf. [22]).

Q-02:  (Andrew Morton [21])
       Is the task_struct pinned by the fd?
A-02:  No. A reference to struct pid is kept. struct pid - as far as I
       understand - was created exactly for the reason to not require to
       pin struct task_struct (cf. [22]).

Q-03: (Andrew Morton [21])
      Does the entire procfs directory remain visible? Just one entry
      within it?
A-03: The same thing that happens right now when you hold a file descriptor
      to /proc/<pid> open (cf. [22]).

Q-04: (Andrew Morton [21])
      Does the pid remain reserved?
A-04: No. This patchset guarantees a stable handle not that pids are not
      recycled (cf. [22]).

Q-05: (Andrew Morton [21])
      Do attempts to signal that fd return errors?
A-05: See {Q,A}-01.

Q-06: (Andrew Morton [22])
      Is there a cleaner way of obtaining the fd? Another syscall perhaps.
A-06: Userspace can already trivially retrieve file descriptors from procfs
      so this is something that we will need to support anyway. Hence,
      there's no immediate need to add another syscalls just to make
      pidfd_send_signal() not dependent on the presence of procfs. However,
      adding a syscalls to get such file descriptors is planned for a
      future patchset (cf. [22]).

Q-07: (Andrew Morton [21] and others)
      This fd-for-a-process sounds like a handy thing and people may well
      think up other uses for it in the future, probably unrelated to
      signals. Are the code and the interface designed to permit such
      future applications?
A-07: Yes (cf. [22]).

Q-08: (Andrew Morton [21] and others)
      Now I think about it, why a new syscall? This thing is looking
      rather like an ioctl?
A-08: This has been extensively discussed. It was agreed that a syscall is
      preferred for a variety or reasons. Here are just a few taken from
      prior threads. Syscalls are safer than ioctl()s especially when
      signaling to fds. Processes are a core kernel concept so a syscall
      seems more appropriate. The layout of the syscall with its four
      arguments would require the addition of a custom struct for the
      ioctl() thereby causing at least the same amount or even more
      complexity for userspace than a simple syscall. The new syscall will
      replace multiple other pid-based syscalls (see description above).
      The file-descriptors-for-processes concept introduced with this
      syscall will be extended with other syscalls in the future. See also
      [22], [23] and various other threads already linked in here.

Q-09: (Florian Weimer [24])
      What happens if you use the new interface with an O_PATH descriptor?
A-09:
      pidfds opened as O_PATH fds cannot be used to send signals to a
      process (cf. [2]). Signaling processes through pidfds is the
      equivalent of writing to a file. Thus, this is not an operation that
      operates "purely at the file descriptor level" as required by the
      open(2) manpage. See also [4].

/* References */
[1]:  https://lore.kernel.org/lkml/20181029221037.87724-1-dancol@google.com/
[2]:  https://lore.kernel.org/lkml/874lbtjvtd.fsf@oldenburg2.str.redhat.com/
[3]:  https://lore.kernel.org/lkml/20181204132604.aspfupwjgjx6fhva@brauner.io/
[4]:  https://lore.kernel.org/lkml/20181203180224.fkvw4kajtbvru2ku@brauner.io/
[5]:  https://lore.kernel.org/lkml/20181121213946.GA10795@mail.hallyn.com/
[6]:  https://lore.kernel.org/lkml/20181120103111.etlqp7zop34v6nv4@brauner.io/
[7]:  https://lore.kernel.org/lkml/36323361-90BD-41AF-AB5B-EE0D7BA02C21@amacapital.net/
[8]:  https://lore.kernel.org/lkml/87tvjxp8pc.fsf@xmission.com/
[9]:  https://asciinema.org/a/IQjuCHew6bnq1cr78yuMv16cy
[11]: https://lore.kernel.org/lkml/F53D6D38-3521-4C20-9034-5AF447DF62FF@amacapital.net/
[12]: https://lore.kernel.org/lkml/87zhtjn8ck.fsf@xmission.com/
[13]: https://lore.kernel.org/lkml/871s6u9z6u.fsf@xmission.com/
[14]: https://lore.kernel.org/lkml/20181206231742.xxi4ghn24z4h2qki@brauner.io/
[15]: https://lore.kernel.org/lkml/20181207003124.GA11160@mail.hallyn.com/
[16]: https://lore.kernel.org/lkml/20181207015423.4miorx43l3qhppfz@brauner.io/
[17]: https://lore.kernel.org/lkml/CAGXu5jL8PciZAXvOvCeCU3wKUEB_dU-O3q0tDw4uB_ojMvDEew@mail.gmail.com/
[18]: https://lore.kernel.org/lkml/20181206222746.GB9224@mail.hallyn.com/
[19]: https://lore.kernel.org/lkml/20181208054059.19813-1-christian@brauner.io/
[20]: https://lore.kernel.org/lkml/8736rebl9s.fsf@oldenburg.str.redhat.com/
[21]: https://lore.kernel.org/lkml/20181228152012.dbf0508c2508138efc5f2bbe@linux-foundation.org/
[22]: https://lore.kernel.org/lkml/20181228233725.722tdfgijxcssg76@brauner.io/
[23]: https://lwn.net/Articles/773459/
[24]: https://lore.kernel.org/lkml/8736rebl9s.fsf@oldenburg.str.redhat.com/
[25]: https://lore.kernel.org/lkml/CAK8P3a0ej9NcJM8wXNPbcGUyOUZYX+VLoDFdbenW3s3114oQZw@mail.gmail.com/

Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Jann Horn <jannh@google.com>
Cc: Andy Lutomirsky <luto@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Christian Brauner <christian@brauner.io>
Reviewed-by: Tycho Andersen <tycho@tycho.ws>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Aleksa Sarai <cyphar@cyphar.com>

(cherry picked from commit 3eb39f47934f9d5a3027fe00d906a45fe3a15fad)

Conflicts:
        arch/x86/entry/syscalls/syscall_32.tbl - trivial manual merge
        arch/x86/entry/syscalls/syscall_64.tbl - trivial manual merge
        include/linux/proc_fs.h - trivial manual merge
        include/linux/syscalls.h - trivial manual merge
        include/uapi/asm-generic/unistd.h - trivial manual merge
        kernel/signal.c - struct kernel_siginfo does not exist in 4.9
        kernel/sys_ni.c - cond_syscall is used instead of COND_SYSCALL
        arch/x86/entry/syscalls/syscall_32.tbl
        arch/x86/entry/syscalls/syscall_64.tbl

(1. manual merges because of 4.9 differences
 2. change prepare_kill_siginfo() to use struct siginfo instead of
kernel_siginfo
 3. exclude kill() changes to avoid struct kernel_siginfo usage
 4. exclude copy_siginfo_from_user_any() to avoid struct kernel_siginfo usage
 5. use copy_from_user() instead of copy_siginfo_from_user() in copy_siginfo_from_user_any()
 6. replaced COND_SYSCALL with cond_syscall
 7. Removed __ia32_sys_pidfd_send_signal in arch/x86/entry/syscalls/syscall_32.tbl.
 8. Replaced __x64_sys_pidfd_send_signal with sys_pidfd_send_signal in arch/x86/entry/syscalls/syscall_64.tbl.)

Bug: 135608568
Test: test program using syscall(__NR_pidfd_send_signal,..) to send SIGKILL
Change-Id: I00f1c618b2e9dbafae4d4113ad4d8a1a44b6957c
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-09-03 13:43:55 -07:00
Greg Kroah-Hartman
9595aa8719 Merge 4.9.190 into android-4.9-q
Changes in 4.9.190
	usb: usbfs: fix double-free of usb memory upon submiturb error
	usb: iowarrior: fix deadlock on disconnect
	sound: fix a memory leak bug
	x86/mm: Check for pfn instead of page in vmalloc_sync_one()
	x86/mm: Sync also unmappings in vmalloc_sync_all()
	mm/vmalloc: Sync unmappings in __purge_vmap_area_lazy()
	perf record: Fix wrong size in perf_record_mmap for last kernel module
	perf db-export: Fix thread__exec_comm()
	perf record: Fix module size on s390
	usb: yurex: Fix use-after-free in yurex_delete
	can: peak_usb: fix potential double kfree_skb()
	netfilter: nfnetlink: avoid deadlock due to synchronous request_module
	iscsi_ibft: make ISCSI_IBFT dependson ACPI instead of ISCSI_IBFT_FIND
	mac80211: don't warn about CW params when not using them
	hwmon: (nct6775) Fix register address and added missed tolerance for nct6106
	cpufreq/pasemi: fix use-after-free in pas_cpufreq_cpu_init()
	s390/qdio: add sanity checks to the fast-requeue path
	ALSA: compress: Fix regression on compressed capture streams
	ALSA: compress: Prevent bypasses of set_params
	ALSA: compress: Don't allow paritial drain operations on capture streams
	ALSA: compress: Be more restrictive about when a drain is allowed
	perf probe: Avoid calling freeing routine multiple times for same pointer
	drbd: dynamically allocate shash descriptor
	ACPI/IORT: Fix off-by-one check in iort_dev_find_its_id()
	ARM: davinci: fix sleep.S build error on ARMv4
	scsi: megaraid_sas: fix panic on loading firmware crashdump
	scsi: ibmvfc: fix WARN_ON during event pool release
	scsi: scsi_dh_alua: always use a 2 second delay before retrying RTPG
	tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loop
	perf/core: Fix creating kernel counters for PMUs that override event->cpu
	can: peak_usb: pcan_usb_pro: Fix info-leaks to USB devices
	can: peak_usb: pcan_usb_fd: Fix info-leaks to USB devices
	hwmon: (nct7802) Fix wrong detection of in4 presence
	ALSA: firewire: fix a memory leak bug
	ALSA: hda - Don't override global PCM hw info flag
	mac80211: don't WARN on short WMM parameters from AP
	SMB3: Fix deadlock in validate negotiate hits reconnect
	smb3: send CAP_DFS capability during session setup
	mwifiex: fix 802.11n/WPA detection
	iwlwifi: don't unmap as page memory that was mapped as single
	scsi: mpt3sas: Use 63-bit DMA addressing on SAS35 HBA
	sh: kernel: hw_breakpoint: Fix missing break in switch statement
	mm/usercopy: use memory range to be accessed for wraparound check
	mm/memcontrol.c: fix use after free in mem_cgroup_iter()
	bpf: get rid of pure_initcall dependency to enable jits
	bpf: restrict access to core bpf sysctls
	bpf: add bpf_jit_limit knob to restrict unpriv allocations
	vhost-net: set packet weight of tx polling to 2 * vq size
	vhost_net: use packet weight for rx handler, too
	vhost_net: introduce vhost_exceeds_weight()
	vhost: introduce vhost_exceeds_weight()
	vhost_net: fix possible infinite loop
	vhost: scsi: add weight support
	siphash: add cryptographically secure PRF
	siphash: implement HalfSipHash1-3 for hash tables
	inet: switch IP ID generator to siphash
	netfilter: ctnetlink: don't use conntrack/expect object addresses as id
	xtensa: add missing isync to the cpu_reset TLB code
	ALSA: hda - Fix a memory leak bug
	ALSA: hda - Add a generic reboot_notify
	ALSA: hda - Let all conexant codec enter D3 when rebooting
	HID: holtek: test for sanity of intfdata
	HID: hiddev: avoid opening a disconnected device
	HID: hiddev: do cleanup in failure of opening a device
	Input: kbtab - sanity check for endpoint type
	Input: iforce - add sanity checks
	net: usb: pegasus: fix improper read if get_registers() fail
	xen/pciback: remove set but not used variable 'old_state'
	irqchip/irq-imx-gpcv2: Forward irq type to parent
	perf header: Fix divide by zero error if f_header.attr_size==0
	perf header: Fix use of unitialized value warning
	libata: zpodd: Fix small read overflow in zpodd_get_mech_type()
	scsi: hpsa: correct scsi command status issue after reset
	ata: libahci: do not complain in case of deferred probe
	kbuild: modpost: handle KBUILD_EXTRA_SYMBOLS only for external modules
	arm64/efi: fix variable 'si' set but not used
	arm64/mm: fix variable 'pud' set but not used
	IB/core: Add mitigation for Spectre V1
	IB/mad: Fix use-after-free in ib mad completion handling
	ocfs2: remove set but not used variable 'last_hash'
	staging: comedi: dt3000: Fix signed integer overflow 'divider * base'
	staging: comedi: dt3000: Fix rounding up of timer divisor
	USB: core: Fix races in character device registration and deregistraion
	usb: cdc-acm: make sure a refcount is taken early enough
	USB: CDC: fix sanity checks in CDC union parser
	USB: serial: option: add D-Link DWM-222 device ID
	USB: serial: option: Add support for ZTE MF871A
	USB: serial: option: add the BroadMobi BM818 card
	USB: serial: option: Add Motorola modem UARTs
	asm-generic: fix -Wtype-limits compiler warnings
	bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K
	arm64: compat: Allow single-byte watchpoints on all addresses
	netfilter: conntrack: Use consistent ct id hash calculation
	Input: psmouse - fix build error of multiple definition
	iommu/amd: Move iommu_init_pci() to .init section
	bnx2x: Fix VF's VLAN reconfiguration in reload.
	net/packet: fix race in tpacket_snd()
	sctp: fix the transport error_count check
	xen/netback: Reset nr_frags before freeing skb
	net/mlx5e: Only support tx/rx pause setting for port owner
	net/mlx5e: Use flow keys dissector to parse packets for ARFS
	team: Add vlan tx offload to hw_enc_features
	bonding: Add vlan tx offload to hw_enc_features
	Linux 4.9.190

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-08-25 14:53:01 +02:00
Daniel Borkmann
6c1dc8f96b bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K
[ Upstream commit fdadd04931c2d7cd294dc5b2b342863f94be53a3 ]

Michael and Sandipan report:

  Commit ede95a63b5 introduced a bpf_jit_limit tuneable to limit BPF
  JIT allocations. At compile time it defaults to PAGE_SIZE * 40000,
  and is adjusted again at init time if MODULES_VADDR is defined.

  For ppc64 kernels, MODULES_VADDR isn't defined, so we're stuck with
  the compile-time default at boot-time, which is 0x9c400000 when
  using 64K page size. This overflows the signed 32-bit bpf_jit_limit
  value:

  root@ubuntu:/tmp# cat /proc/sys/net/core/bpf_jit_limit
  -1673527296

  and can cause various unexpected failures throughout the network
  stack. In one case `strace dhclient eth0` reported:

  setsockopt(5, SOL_SOCKET, SO_ATTACH_FILTER, {len=11, filter=0x105dd27f8},
             16) = -1 ENOTSUPP (Unknown error 524)

  and similar failures can be seen with tools like tcpdump. This doesn't
  always reproduce however, and I'm not sure why. The more consistent
  failure I've seen is an Ubuntu 18.04 KVM guest booted on a POWER9
  host would time out on systemd/netplan configuring a virtio-net NIC
  with no noticeable errors in the logs.

Given this and also given that in near future some architectures like
arm64 will have a custom area for BPF JIT image allocations we should
get rid of the BPF_JIT_LIMIT_DEFAULT fallback / default entirely. For
4.21, we have an overridable bpf_jit_alloc_exec(), bpf_jit_free_exec()
so therefore add another overridable bpf_jit_alloc_exec_limit() helper
function which returns the possible size of the memory area for deriving
the default heuristic in bpf_jit_charge_init().

Like bpf_jit_alloc_exec() and bpf_jit_free_exec(), the new
bpf_jit_alloc_exec_limit() assumes that module_alloc() is the default
JIT memory provider, and therefore in case archs implement their custom
module_alloc() we use MODULES_{END,_VADDR} for limits and otherwise for
vmalloc_exec() cases like on ppc64 we use VMALLOC_{END,_START}.

Additionally, for archs supporting large page sizes, we should change
the sysctl to be handled as long to not run into sysctl restrictions
in future.

Fixes: ede95a63b5e8 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations")
Reported-by: Sandipan Das <sandipan@linux.ibm.com>
Reported-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-25 10:51:50 +02:00
Eric Dumazet
b97a2f3d58 inet: switch IP ID generator to siphash
commit df453700e8d81b1bdafdf684365ee2b9431fb702 upstream.

According to Amit Klein and Benny Pinkas, IP ID generation is too weak
and might be used by attackers.

Even with recent net_hash_mix() fix (netns: provide pure entropy for net_hash_mix())
having 64bit key and Jenkins hash is risky.

It is time to switch to siphash and its 128bit keys.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-25 10:51:42 +02:00
Jason A. Donenfeld
175a407ce4 siphash: implement HalfSipHash1-3 for hash tables
commit 1ae2324f732c9c4e2fa4ebd885fa1001b70d52e1 upstream.

HalfSipHash, or hsiphash, is a shortened version of SipHash, which
generates 32-bit outputs using a weaker 64-bit key. It has *much* lower
security margins, and shouldn't be used for anything too sensitive, but
it could be used as a hashtable key function replacement, if the output
is never exposed, and if the security requirement is not too high.

The goal is to make this something that performance-critical jhash users
would be willing to use.

On 64-bit machines, HalfSipHash1-3 is slower than SipHash1-3, so we alias
SipHash1-3 to HalfSipHash1-3 on those systems.

64-bit x86_64:
[    0.509409] test_siphash:     SipHash2-4 cycles: 4049181
[    0.510650] test_siphash:     SipHash1-3 cycles: 2512884
[    0.512205] test_siphash: HalfSipHash1-3 cycles: 3429920
[    0.512904] test_siphash:    JenkinsHash cycles:  978267
So, we map hsiphash() -> SipHash1-3

32-bit x86:
[    0.509868] test_siphash:     SipHash2-4 cycles: 14812892
[    0.513601] test_siphash:     SipHash1-3 cycles:  9510710
[    0.515263] test_siphash: HalfSipHash1-3 cycles:  3856157
[    0.515952] test_siphash:    JenkinsHash cycles:  1148567
So, we map hsiphash() -> HalfSipHash1-3

hsiphash() is roughly 3 times slower than jhash(), but comes with a
considerable security improvement.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.9 to avoid regression for WireGuard with only half
 the siphash API present]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-25 10:51:42 +02:00
Jason A. Donenfeld
53e054b3cd siphash: add cryptographically secure PRF
commit 2c956a60778cbb6a27e0c7a8a52a91378c90e1d1 upstream.

SipHash is a 64-bit keyed hash function that is actually a
cryptographically secure PRF, like HMAC. Except SipHash is super fast,
and is meant to be used as a hashtable keyed lookup function, or as a
general PRF for short input use cases, such as sequence numbers or RNG
chaining.

For the first usage:

There are a variety of attacks known as "hashtable poisoning" in which an
attacker forms some data such that the hash of that data will be the
same, and then preceeds to fill up all entries of a hashbucket. This is
a realistic and well-known denial-of-service vector. Currently
hashtables use jhash, which is fast but not secure, and some kind of
rotating key scheme (or none at all, which isn't good). SipHash is meant
as a replacement for jhash in these cases.

There are a modicum of places in the kernel that are vulnerable to
hashtable poisoning attacks, either via userspace vectors or network
vectors, and there's not a reliable mechanism inside the kernel at the
moment to fix it. The first step toward fixing these issues is actually
getting a secure primitive into the kernel for developers to use. Then
we can, bit by bit, port things over to it as deemed appropriate.

While SipHash is extremely fast for a cryptographically secure function,
it is likely a bit slower than the insecure jhash, and so replacements
will be evaluated on a case-by-case basis based on whether or not the
difference in speed is negligible and whether or not the current jhash usage
poses a real security risk.

For the second usage:

A few places in the kernel are using MD5 or SHA1 for creating secure
sequence numbers, syn cookies, port numbers, or fast random numbers.
SipHash is a faster and more fitting, and more secure replacement for MD5
in those situations. Replacing MD5 and SHA1 with SipHash for these uses is
obvious and straight-forward, and so is submitted along with this patch
series. There shouldn't be much of a debate over its efficacy.

Dozens of languages are already using this internally for their hash
tables and PRFs. Some of the BSDs already use this in their kernels.
SipHash is a widely known high-speed solution to a widely known set of
problems, and it's time we catch-up.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Jean-Philippe Aumasson <jeanphilippe.aumasson@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Biggers <ebiggers3@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 4.9 as dependency of commits df453700e8d8 "inet: switch
 IP ID generator to siphash" and 3c79107631db "netfilter: ctnetlink: don't
 use conntrack/expect object addresses as id"]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-25 10:51:42 +02:00
Daniel Borkmann
c98446e1ba bpf: add bpf_jit_limit knob to restrict unpriv allocations
commit ede95a63b5e84ddeea6b0c473b36ab8bfd8c6ce3 upstream.

Rick reported that the BPF JIT could potentially fill the entire module
space with BPF programs from unprivileged users which would prevent later
attempts to load normal kernel modules or privileged BPF programs, for
example. If JIT was enabled but unsuccessful to generate the image, then
before commit 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config")
we would always fall back to the BPF interpreter. Nowadays in the case
where the CONFIG_BPF_JIT_ALWAYS_ON could be set, then the load will abort
with a failure since the BPF interpreter was compiled out.

Add a global limit and enforce it for unprivileged users such that in case
of BPF interpreter compiled out we fail once the limit has been reached
or we fall back to BPF interpreter earlier w/o using module mem if latter
was compiled in. In a next step, fair share among unprivileged users can
be resolved in particular for the case where we would fail hard once limit
is reached.

Fixes: 290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config")
Fixes: 0a14842f5a ("net: filter: Just In Time compiler for x86-64")
Co-Developed-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-25 10:51:41 +02:00
Felix Jia
1524ee00a2 UPSTREAM: net/ipv6: allow sysctl to change link-local address generation mode
The address generation mode for IPv6 link-local can only be configured
by netlink messages. This patch adds the ability to change the address
generation mode via sysctl.

v1 -> v2
Removed the rtnl lock and switch to use RCU lock to iterate through
the netdev list.

v2 -> v3
Removed the addrgenmode variable from the idev structure and use the
systcl storage for the flag.

Simplifed the logic for sysctl handling by removing the supported
for all operation.

Added support for more types of tunnel interfaces for link-local
address generation.

Based the patches from net-next.

v3 -> v4
Removed unnecessary whitespace changes.

Signed-off-by: Felix Jia <felix.jia@alliedtelesis.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>

(cherry picked from commit d35a00b8e33dab7385f724e713ae71c8be0a49f4)
Bug: 138428295
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ia526e6c1de55e51e35b4b83d95749121fee5d0d1
2019-08-15 21:01:57 +00:00
Greg Kroah-Hartman
94c1fcc8e4 Merge 4.9.189 into android-4.9-q
Changes in 4.9.189
	scsi: fcoe: Embed fc_rport_priv in fcoe_rport structure
	ARM: dts: Add pinmuxing for i2c2 and i2c3 for LogicPD SOM-LV
	ARM: dts: Add pinmuxing for i2c2 and i2c3 for LogicPD torpedo
	ARM: dts: logicpd-som-lv: Fix Audio Mute
	arm64: cpufeature: Fix CTR_EL0 field definitions
	arm64: cpufeature: Fix feature comparison for CTR_EL0.{CWG,ERG}
	tcp: be more careful in tcp_fragment()
	HID: wacom: fix bit shift for Cintiq Companion 2
	HID: Add quirk for HP X1200 PIXART OEM mouse
	RDMA: Directly cast the sockaddr union to sockaddr
	IB: directly cast the sockaddr union to aockaddr
	objtool: Add machine_real_restart() to the noreturn list
	objtool: Add rewind_stack_do_exit() to the noreturn list
	libceph: use kbasename() and kill ceph_file_part()
	atm: iphase: Fix Spectre v1 vulnerability
	net: bridge: delete local fdb on device init failure
	net: bridge: mcast: don't delete permanent entries when fast leave is enabled
	net: fix ifindex collision during namespace removal
	net/mlx5: Use reversed order when unregister devices
	net: sched: Fix a possible null-pointer dereference in dequeue_func()
	tipc: compat: allow tipc commands without arguments
	compat_ioctl: pppoe: fix PPPOEIOCSFWD handling
	ip6_tunnel: fix possible use-after-free on xmit
	ife: error out when nla attributes are empty
	bnx2x: Disable multi-cos feature.
	block: blk_init_allocated_queue() set q->fq as NULL in the fail case
	spi: bcm2835: Fix 3-wire mode if DMA is enabled
	x86: cpufeatures: Sort feature word 7
	x86/speculation: Prepare entry code for Spectre v1 swapgs mitigations
	x86/speculation: Enable Spectre v1 swapgs mitigations
	x86/entry/64: Use JMP instead of JMPQ
	x86/speculation/swapgs: Exclude ATOMs from speculation through SWAPGS
	Linux 4.9.189

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-08-11 15:30:44 +02:00
Arnd Bergmann
00a8794f63 compat_ioctl: pppoe: fix PPPOEIOCSFWD handling
[ Upstream commit 055d88242a6046a1ceac3167290f054c72571cd9 ]

Support for handling the PPPOEIOCSFWD ioctl in compat mode was added in
linux-2.5.69 along with hundreds of other commands, but was always broken
sincen only the structure is compatible, but the command number is not,
due to the size being sizeof(size_t), or at first sizeof(sizeof((struct
sockaddr_pppox)), which is different on 64-bit architectures.

Guillaume Nault adds:

  And the implementation was broken until 2016 (see 29e73269aa ("pppoe:
  fix reference counting in PPPoE proxy")), and nobody ever noticed. I
  should probably have removed this ioctl entirely instead of fixing it.
  Clearly, it has never been used.

Fix it by adding a compat_ioctl handler for all pppoe variants that
translates the command number and then calls the regular ioctl function.

All other ioctl commands handled by pppoe are compatible between 32-bit
and 64-bit, and require compat_ptr() conversion.

This should apply to all stable kernels.

Acked-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-11 12:22:17 +02:00
Ilya Dryomov
22395a3e46 libceph: use kbasename() and kill ceph_file_part()
commit 6f4dbd149d2a151b89d1a5bbf7530ee5546c7908 upstream.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-11 12:22:15 +02:00
Greg Kroah-Hartman
4ebd29edaf Merge 4.9.188 into android-4.9-q
Changes in 4.9.188
	ARM: riscpc: fix DMA
	ARM: dts: rockchip: Make rk3288-veyron-minnie run at hs200
	ARM: dts: rockchip: Make rk3288-veyron-mickey's emmc work again
	ARM: dts: rockchip: Mark that the rk3288 timer might stop in suspend
	ftrace: Enable trampoline when rec count returns back to one
	kernel/module.c: Only return -EEXIST for modules that have finished loading
	MIPS: lantiq: Fix bitfield masking
	dmaengine: rcar-dmac: Reject zero-length slave DMA requests
	fs/adfs: super: fix use-after-free bug
	btrfs: fix minimum number of chunk errors for DUP
	ceph: fix improper use of smp_mb__before_atomic()
	ceph: return -ERANGE if virtual xattr value didn't fit in buffer
	scsi: zfcp: fix GCC compiler warning emitted with -Wmaybe-uninitialized
	ACPI: fix false-positive -Wuninitialized warning
	be2net: Signal that the device cannot transmit during reconfiguration
	x86/apic: Silence -Wtype-limits compiler warnings
	x86: math-emu: Hide clang warnings for 16-bit overflow
	mm/cma.c: fail if fixed declaration can't be honored
	coda: add error handling for fget
	coda: fix build using bare-metal toolchain
	uapi linux/coda_psdev.h: move upc_req definition from uapi to kernel side headers
	drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings
	ipc/mqueue.c: only perform resource calculation if user valid
	x86/kvm: Don't call kvm_spurious_fault() from .fixup
	x86, boot: Remove multiple copy of static function sanitize_boot_params()
	kbuild: initialize CLANG_FLAGS correctly in the top Makefile
	Btrfs: fix incremental send failure after deduplication
	mmc: dw_mmc: Fix occasional hang after tuning on eMMC
	gpiolib: fix incorrect IRQ requesting of an active-low lineevent
	selinux: fix memory leak in policydb_init()
	s390/dasd: fix endless loop after read unit address configuration
	drivers/perf: arm_pmu: Fix failure path in PM notifier
	xen/swiotlb: fix condition for calling xen_destroy_contiguous_region()
	IB/mlx5: Fix RSS Toeplitz setup to be aligned with the HW specification
	coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping
	infiniband: fix race condition between infiniband mlx4, mlx5 driver and core dumping
	coredump: fix race condition between collapse_huge_page() and core dumping
	eeprom: at24: make spd world-readable again
	Backport minimal compiler_attributes.h to support GCC 9
	include/linux/module.h: copy __init/__exit attrs to init/cleanup_module
	objtool: Support GCC 9 cold subfunction naming scheme
	x86, mm, gup: prevent get_page() race with munmap in paravirt guest
	Linux 4.9.188

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-08-06 18:45:16 +02:00
Miguel Ojeda
2c34c215c1 include/linux/module.h: copy __init/__exit attrs to init/cleanup_module
commit a6e60d84989fa0e91db7f236eda40453b0e44afa upstream.

The upcoming GCC 9 release extends the -Wmissing-attributes warnings
(enabled by -Wall) to C and aliases: it warns when particular function
attributes are missing in the aliases but not in their target.

In particular, it triggers for all the init/cleanup_module
aliases in the kernel (defined by the module_init/exit macros),
ending up being very noisy.

These aliases point to the __init/__exit functions of a module,
which are defined as __cold (among other attributes). However,
the aliases themselves do not have the __cold attribute.

Since the compiler behaves differently when compiling a __cold
function as well as when compiling paths leading to calls
to __cold functions, the warning is trying to point out
the possibly-forgotten attribute in the alias.

In order to keep the warning enabled, we decided to silence
this case. Ideally, we would mark the aliases directly
as __init/__exit. However, there are currently around 132 modules
in the kernel which are missing __init/__exit in their init/cleanup
functions (either because they are missing, or for other reasons,
e.g. the functions being called from somewhere else); and
a section mismatch is a hard error.

A conservative alternative was to mark the aliases as __cold only.
However, since we would like to eventually enforce __init/__exit
to be always marked,  we chose to use the new __copy function
attribute (introduced by GCC 9 as well to deal with this).
With it, we copy the attributes used by the target functions
into the aliases. This way, functions that were not marked
as __init/__exit won't have their aliases marked either,
and therefore there won't be a section mismatch.

Note that the warning would go away marking either the extern
declaration, the definition, or both. However, we only mark
the definition of the alias, since we do not want callers
(which only see the declaration) to be compiled as if the function
was __cold (and therefore the paths leading to those calls
would be assumed to be unlikely).

Link: https://lore.kernel.org/lkml/259986242.BvXPX32bHu@devpool35/
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/lkml/20190123173707.GA16603@gmail.com/
Link: https://lore.kernel.org/lkml/20190206175627.GA20399@gmail.com/
Suggested-by: Martin Sebor <msebor@gcc.gnu.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06 18:29:42 +02:00
Miguel Ojeda
fe5844365e Backport minimal compiler_attributes.h to support GCC 9
This adds support for __copy to v4.9.y so that we can use it in
init/exit_module to avoid -Werror=missing-attributes errors on GCC 9.

Link: https://lore.kernel.org/lkml/259986242.BvXPX32bHu@devpool35/
Cc: <stable@vger.kernel.org>
Suggested-by: Rolf Eike Beer <eb@emlix.com>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06 18:29:42 +02:00
Andrea Arcangeli
d4fc64c927 coredump: fix race condition between collapse_huge_page() and core dumping
commit 59ea6d06cfa9247b586a695c21f94afa7183af74 upstream.

When fixing the race conditions between the coredump and the mmap_sem
holders outside the context of the process, we focused on
mmget_not_zero()/get_task_mm() callers in 04f5866e41fb70 ("coredump: fix
race condition between mmget_not_zero()/get_task_mm() and core
dumping"), but those aren't the only cases where the mmap_sem can be
taken outside of the context of the process as Michal Hocko noticed
while backporting that commit to older -stable kernels.

If mmgrab() is called in the context of the process, but then the
mm_count reference is transferred outside the context of the process,
that can also be a problem if the mmap_sem has to be taken for writing
through that mm_count reference.

khugepaged registration calls mmgrab() in the context of the process,
but the mmap_sem for writing is taken later in the context of the
khugepaged kernel thread.

collapse_huge_page() after taking the mmap_sem for writing doesn't
modify any vma, so it's not obvious that it could cause a problem to the
coredump, but it happens to modify the pmd in a way that breaks an
invariant that pmd_trans_huge_lock() relies upon.  collapse_huge_page()
needs the mmap_sem for writing just to block concurrent page faults that
call pmd_trans_huge_lock().

Specifically the invariant that "!pmd_trans_huge()" cannot become a
"pmd_trans_huge()" doesn't hold while collapse_huge_page() runs.

The coredump will call __get_user_pages() without mmap_sem for reading,
which eventually can invoke a lockless page fault which will need a
functional pmd_trans_huge_lock().

So collapse_huge_page() needs to use mmget_still_valid() to check it's
not running concurrently with the coredump...  as long as the coredump
can invoke page faults without holding the mmap_sem for reading.

This has "Fixes: khugepaged" to facilitate backporting, but in my view
it's more a bug in the coredump code that will eventually have to be
rewritten to stop invoking page faults without the mmap_sem for reading.
So the long term plan is still to drop all mmget_still_valid().

Link: http://lkml.kernel.org/r/20190607161558.32104-1-aarcange@redhat.com
Fixes: ba76149f47 ("thp: khugepaged")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Michal Hocko <mhocko@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[Ajay: Just adjusted to apply on v4.9]
Signed-off-by: Ajay Kaher <akaher@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06 18:29:41 +02:00
Andrea Arcangeli
16903f1a5b coredump: fix race condition between mmget_not_zero()/get_task_mm() and core dumping
commit 04f5866e41fb70690e28397487d8bd8eea7d712a upstream.

The core dumping code has always run without holding the mmap_sem for
writing, despite that is the only way to ensure that the entire vma
layout will not change from under it.  Only using some signal
serialization on the processes belonging to the mm is not nearly enough.
This was pointed out earlier.  For example in Hugh's post from Jul 2017:

  https://lkml.kernel.org/r/alpine.LSU.2.11.1707191716030.2055@eggly.anvils

  "Not strictly relevant here, but a related note: I was very surprised
   to discover, only quite recently, how handle_mm_fault() may be called
   without down_read(mmap_sem) - when core dumping. That seems a
   misguided optimization to me, which would also be nice to correct"

In particular because the growsdown and growsup can move the
vm_start/vm_end the various loops the core dump does around the vma will
not be consistent if page faults can happen concurrently.

Pretty much all users calling mmget_not_zero()/get_task_mm() and then
taking the mmap_sem had the potential to introduce unexpected side
effects in the core dumping code.

Adding mmap_sem for writing around the ->core_dump invocation is a
viable long term fix, but it requires removing all copy user and page
faults and to replace them with get_dump_page() for all binary formats
which is not suitable as a short term fix.

For the time being this solution manually covers the places that can
confuse the core dump either by altering the vma layout or the vma flags
while it runs.  Once ->core_dump runs under mmap_sem for writing the
function mmget_still_valid() can be dropped.

Allowing mmap_sem protected sections to run in parallel with the
coredump provides some minor parallelism advantage to the swapoff code
(which seems to be safe enough by never mangling any vma field and can
keep doing swapins in parallel to the core dumping) and to some other
corner case.

In order to facilitate the backporting I added "Fixes: 86039bd3b4e6"
however the side effect of this same race condition in /proc/pid/mem
should be reproducible since before 2.6.12-rc2 so I couldn't add any
other "Fixes:" because there's no hash beyond the git genesis commit.

Because find_extend_vma() is the only location outside of the process
context that could modify the "mm" structures under mmap_sem for
reading, by adding the mmget_still_valid() check to it, all other cases
that take the mmap_sem for reading don't need the new check after
mmget_not_zero()/get_task_mm().  The expand_stack() in page fault
context also doesn't need the new check, because all tasks under core
dumping are frozen.

Link: http://lkml.kernel.org/r/20190325224949.11068-1-aarcange@redhat.com
Fixes: 86039bd3b4 ("userfaultfd: add new syscall to provide memory externalization")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Jann Horn <jannh@google.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jann Horn <jannh@google.com>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[akaher@vmware.com: stable 4.9 backport
-  handle binder_update_page_range - mhocko@suse.com]
Signed-off-by: Ajay Kaher <akaher@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06 18:29:41 +02:00
Mikko Rapeli
317fc4dd52 uapi linux/coda_psdev.h: move upc_req definition from uapi to kernel side headers
[ Upstream commit f90fb3c7e2c13ae829db2274b88b845a75038b8a ]

Only users of upc_req in kernel side fs/coda/psdev.c and
fs/coda/upcall.c already include linux/coda_psdev.h.

Suggested by Jan Harkes <jaharkes@cs.cmu.edu> in
  https://lore.kernel.org/lkml/20150531111913.GA23377@cs.cmu.edu/

Fixes these include/uapi/linux/coda_psdev.h compilation errors in userspace:

  linux/coda_psdev.h:12:19: error: field `uc_chain' has incomplete type
  struct list_head    uc_chain;
                   ^
  linux/coda_psdev.h:13:2: error: unknown type name `caddr_t'
  caddr_t             uc_data;
  ^
  linux/coda_psdev.h:14:2: error: unknown type name `u_short'
  u_short             uc_flags;
  ^
  linux/coda_psdev.h:15:2: error: unknown type name `u_short'
  u_short             uc_inSize;  /* Size is at most 5000 bytes */
  ^
  linux/coda_psdev.h:16:2: error: unknown type name `u_short'
  u_short             uc_outSize;
  ^
  linux/coda_psdev.h:17:2: error: unknown type name `u_short'
  u_short             uc_opcode;  /* copied from data to save lookup */
  ^
  linux/coda_psdev.h:19:2: error: unknown type name `wait_queue_head_t'
  wait_queue_head_t   uc_sleep;   /* process' wait queue */
  ^

Link: http://lkml.kernel.org/r/9f99f5ce6a0563d5266e6cf7aa9585aac2cae971.1558117389.git.jaharkes@cs.cmu.edu
Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Sam Protsenko <semen.protsenko@linaro.org>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Zhouyang Jia <jiazhouyang09@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-06 18:29:38 +02:00
Sam Protsenko
90320a506c coda: fix build using bare-metal toolchain
[ Upstream commit b2a57e334086602be56b74958d9f29b955cd157f ]

The kernel is self-contained project and can be built with bare-metal
toolchain.  But bare-metal toolchain doesn't define __linux__.  Because
of this u_quad_t type is not defined when using bare-metal toolchain and
codafs build fails.  This patch fixes it by defining u_quad_t type
unconditionally.

Link: http://lkml.kernel.org/r/3cbb40b0a57b6f9923a9d67b53473c0b691a3eaa.1558117389.git.jaharkes@cs.cmu.edu
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Mikko Rapeli <mikko.rapeli@iki.fi>
Cc: Yann Droneaud <ydroneaud@opteya.com>
Cc: Zhouyang Jia <jiazhouyang09@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-06 18:29:38 +02:00
Arnd Bergmann
0153dbcbd4 ACPI: fix false-positive -Wuninitialized warning
[ Upstream commit dfd6f9ad36368b8dbd5f5a2b2f0a4705ae69a323 ]

clang gets confused by an uninitialized variable in what looks
to it like a never executed code path:

arch/x86/kernel/acpi/boot.c:618:13: error: variable 'polarity' is uninitialized when used here [-Werror,-Wuninitialized]
        polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
                   ^~~~~~~~
arch/x86/kernel/acpi/boot.c:606:32: note: initialize the variable 'polarity' to silence this warning
        int rc, irq, trigger, polarity;
                                      ^
                                       = 0
arch/x86/kernel/acpi/boot.c:617:12: error: variable 'trigger' is uninitialized when used here [-Werror,-Wuninitialized]
        trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
                  ^~~~~~~
arch/x86/kernel/acpi/boot.c:606:22: note: initialize the variable 'trigger' to silence this warning
        int rc, irq, trigger, polarity;
                            ^
                             = 0

This is unfortunately a design decision in clang and won't be fixed.

Changing the acpi_get_override_irq() macro to an inline function
reliably avoids the issue.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-06 18:29:36 +02:00
Greg Kroah-Hartman
0eb90dd8f7 Merge 4.9.187 into android-4.9-q
Changes in 4.9.187
	MIPS: ath79: fix ar933x uart parity mode
	MIPS: fix build on non-linux hosts
	arm64/efi: Mark __efistub_stext_offset as an absolute symbol explicitly
	dmaengine: imx-sdma: fix use-after-free on probe error path
	ath10k: Do not send probe response template for mesh
	ath9k: Check for errors when reading SREV register
	ath6kl: add some bounds checking
	ath: DFS JP domain W56 fixed pulse type 3 RADAR detection
	batman-adv: fix for leaked TVLV handler.
	media: dvb: usb: fix use after free in dvb_usb_device_exit
	crypto: talitos - fix skcipher failure due to wrong output IV
	media: marvell-ccic: fix DMA s/g desc number calculation
	media: vpss: fix a potential NULL pointer dereference
	media: media_device_enum_links32: clean a reserved field
	net: stmmac: dwmac1000: Clear unused address entries
	net: stmmac: dwmac4/5: Clear unused address entries
	signal/pid_namespace: Fix reboot_pid_ns to use send_sig not force_sig
	af_key: fix leaks in key_pol_get_resp and dump_sp.
	xfrm: Fix xfrm sel prefix length validation
	media: mc-device.c: don't memset __user pointer contents
	media: staging: media: davinci_vpfe: - Fix for memory leak if decoder initialization fails.
	net: phy: Check against net_device being NULL
	crypto: talitos - properly handle split ICV.
	crypto: talitos - Align SEC1 accesses to 32 bits boundaries.
	tua6100: Avoid build warnings.
	locking/lockdep: Fix merging of hlocks with non-zero references
	media: wl128x: Fix some error handling in fm_v4l2_init_video_device()
	cpupower : frequency-set -r option misses the last cpu in related cpu list
	net: fec: Do not use netdev messages too early
	net: axienet: Fix race condition causing TX hang
	s390/qdio: handle PENDING state for QEBSM devices
	perf cs-etm: Properly set the value of 'old' and 'head' in snapshot mode
	perf test 6: Fix missing kvm module load for s390
	gpio: omap: fix lack of irqstatus_raw0 for OMAP4
	gpio: omap: ensure irq is enabled before wakeup
	regmap: fix bulk writes on paged registers
	bpf: silence warning messages in core
	rcu: Force inlining of rcu_read_lock()
	blkcg, writeback: dead memcgs shouldn't contribute to writeback ownership arbitration
	xfrm: fix sa selector validation
	perf evsel: Make perf_evsel__name() accept a NULL argument
	vhost_net: disable zerocopy by default
	ipoib: correcly show a VF hardware address
	EDAC/sysfs: Fix memory leak when creating a csrow object
	ipsec: select crypto ciphers for xfrm_algo
	media: i2c: fix warning same module names
	ntp: Limit TAI-UTC offset
	timer_list: Guard procfs specific code
	acpi/arm64: ignore 5.1 FADTs that are reported as 5.0
	media: coda: fix mpeg2 sequence number handling
	media: coda: increment sequence offset for the last returned frame
	mt7601u: do not schedule rx_tasklet when the device has been disconnected
	x86/build: Add 'set -e' to mkcapflags.sh to delete broken capflags.c
	mt7601u: fix possible memory leak when the device is disconnected
	ath10k: fix PCIE device wake up failed
	perf tools: Increase MAX_NR_CPUS and MAX_CACHES
	libata: don't request sense data on !ZAC ATA devices
	clocksource/drivers/exynos_mct: Increase priority over ARM arch timer
	rslib: Fix decoding of shortened codes
	rslib: Fix handling of of caller provided syndrome
	ixgbe: Check DDM existence in transceiver before access
	crypto: asymmetric_keys - select CRYPTO_HASH where needed
	EDAC: Fix global-out-of-bounds write when setting edac_mc_poll_msec
	bcache: check c->gc_thread by IS_ERR_OR_NULL in cache_set_flush()
	iwlwifi: mvm: Drop large non sta frames
	net: usb: asix: init MAC address buffers
	gpiolib: Fix references to gpiod_[gs]et_*value_cansleep() variants
	Bluetooth: hci_bcsp: Fix memory leak in rx_skb
	Bluetooth: 6lowpan: search for destination address in all peers
	Bluetooth: Check state in l2cap_disconnect_rsp
	Bluetooth: validate BLE connection interval updates
	gtp: fix Illegal context switch in RCU read-side critical section.
	gtp: fix use-after-free in gtp_newlink()
	xen: let alloc_xenballooned_pages() fail if not enough memory free
	scsi: NCR5380: Reduce goto statements in NCR5380_select()
	scsi: NCR5380: Always re-enable reselection interrupt
	scsi: mac_scsi: Increase PIO/PDMA transfer length threshold
	crypto: ghash - fix unaligned memory access in ghash_setkey()
	crypto: arm64/sha1-ce - correct digest for empty data in finup
	crypto: arm64/sha2-ce - correct digest for empty data in finup
	crypto: chacha20poly1305 - fix atomic sleep when using async algorithm
	crypto: crypto4xx - fix a potential double free in ppc4xx_trng_probe
	Input: gtco - bounds check collection indent level
	regulator: s2mps11: Fix buck7 and buck8 wrong voltages
	arm64: tegra: Update Jetson TX1 GPU regulator timings
	iwlwifi: pcie: don't service an interrupt that was masked
	tracing/snapshot: Resize spare buffer if size changed
	NFSv4: Handle the special Linux file open access mode
	lib/scatterlist: Fix mapping iterator when sg->offset is greater than PAGE_SIZE
	ALSA: seq: Break too long mutex context in the write loop
	ALSA: hda/realtek: apply ALC891 headset fixup to one Dell machine
	media: v4l2: Test type instead of cfg->type in v4l2_ctrl_new_custom()
	media: coda: Remove unbalanced and unneeded mutex unlock
	KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed
	arm64: tegra: Fix AGIC register range
	fs/proc/proc_sysctl.c: fix the default values of i_uid/i_gid on /proc/sys inodes.
	drm/nouveau/i2c: Enable i2c pads & busses during preinit
	padata: use smp_mb in padata_reorder to avoid orphaned padata jobs
	9p/virtio: Add cleanup path in p9_virtio_init
	PCI: Do not poll for PME if the device is in D3cold
	Btrfs: add missing inode version, ctime and mtime updates when punching hole
	libnvdimm/pfn: fix fsdax-mode namespace info-block zero-fields
	take floppy compat ioctls to sodding floppy.c
	floppy: fix div-by-zero in setup_format_params
	floppy: fix out-of-bounds read in next_valid_format
	floppy: fix invalid pointer dereference in drive_name
	floppy: fix out-of-bounds read in copy_buffer
	coda: pass the host file in vma->vm_file on mmap
	gpu: ipu-v3: ipu-ic: Fix saturation bit offset in TPMEM
	crypto: ccp - Validate the the error value used to index error messages
	PCI: hv: Delete the device earlier from hbus->children for hot-remove
	PCI: hv: Fix a use-after-free bug in hv_eject_device_work()
	crypto: caam - limit output IV to CBC to work around CTR mode DMA issue
	um: Allow building and running on older hosts
	um: Fix FP register size for XSTATE/XSAVE
	parisc: Ensure userspace privilege for ptraced processes in regset functions
	parisc: Fix kernel panic due invalid values in IAOQ0 or IAOQ1
	powerpc/32s: fix suspend/resume when IBATs 4-7 are used
	powerpc/watchpoint: Restore NV GPRs while returning from exception
	eCryptfs: fix a couple type promotion bugs
	intel_th: msu: Fix single mode with disabled IOMMU
	Bluetooth: Add SMP workaround Microsoft Surface Precision Mouse bug
	usb: Handle USB3 remote wakeup for LPM enabled devices correctly
	dm bufio: fix deadlock with loop device
	compiler.h, kasan: Avoid duplicating __read_once_size_nocheck()
	compiler.h: Add read_word_at_a_time() function.
	lib/strscpy: Shut up KASAN false-positives in strscpy()
	ext4: allow directory holes
	bnx2x: Prevent load reordering in tx completion processing
	bnx2x: Prevent ptp_task to be rescheduled indefinitely
	caif-hsi: fix possible deadlock in cfhsi_exit_module()
	igmp: fix memory leak in igmpv3_del_delrec()
	ipv4: don't set IPv6 only flags to IPv4 addresses
	net: bcmgenet: use promisc for unsupported filters
	net: dsa: mv88e6xxx: wait after reset deactivation
	net: neigh: fix multiple neigh timer scheduling
	net: openvswitch: fix csum updates for MPLS actions
	nfc: fix potential illegal memory access
	rxrpc: Fix send on a connected, but unbound socket
	sky2: Disable MSI on ASUS P6T
	vrf: make sure skb->data contains ip header to make routing
	macsec: fix use-after-free of skb during RX
	macsec: fix checksumming after decryption
	netrom: fix a memory leak in nr_rx_frame()
	netrom: hold sock when setting skb->destructor
	bonding: validate ip header before check IPPROTO_IGMP
	tcp: Reset bytes_acked and bytes_received when disconnecting
	net: bridge: mcast: fix stale nsrcs pointer in igmp3/mld2 report handling
	net: bridge: mcast: fix stale ipv6 hdr pointer when handling v6 query
	net: bridge: stp: don't cache eth dest pointer before skb pull
	perf/x86/amd/uncore: Rename 'L2' to 'LLC'
	perf/x86/amd/uncore: Get correct number of cores sharing last level cache
	perf/events/amd/uncore: Fix amd_uncore_llc ID to use pre-defined cpu_llc_id
	NFSv4: Fix open create exclusive when the server reboots
	nfsd: increase DRC cache limit
	nfsd: give out fewer session slots as limit approaches
	nfsd: fix performance-limiting session calculation
	nfsd: Fix overflow causing non-working mounts on 1 TB machines
	drm/panel: simple: Fix panel_simple_dsi_probe
	usb: core: hub: Disable hub-initiated U1/U2
	tty: max310x: Fix invalid baudrate divisors calculator
	pinctrl: rockchip: fix leaked of_node references
	tty: serial: cpm_uart - fix init when SMC is relocated
	drm/bridge: tc358767: read display_props in get_modes()
	drm/bridge: sii902x: pixel clock unit is 10kHz instead of 1kHz
	memstick: Fix error cleanup path of memstick_init
	tty/serial: digicolor: Fix digicolor-usart already registered warning
	tty: serial: msm_serial: avoid system lockup condition
	serial: 8250: Fix TX interrupt handling condition
	drm/virtio: Add memory barriers for capset cache.
	phy: renesas: rcar-gen2: Fix memory leak at error paths
	drm/rockchip: Properly adjust to a true clock in adjusted_mode
	tty: serial_core: Set port active bit in uart_port_activate
	usb: gadget: Zero ffs_io_data
	powerpc/pci/of: Fix OF flags parsing for 64bit BARs
	PCI: sysfs: Ignore lockdep for remove attribute
	kbuild: Add -Werror=unknown-warning-option to CLANG_FLAGS
	PCI: xilinx-nwl: Fix Multi MSI data programming
	iio: iio-utils: Fix possible incorrect mask calculation
	recordmcount: Fix spurious mcount entries on powerpc
	mfd: core: Set fwnode for created devices
	mfd: arizona: Fix undefined behavior
	mfd: hi655x-pmic: Fix missing return value check for devm_regmap_init_mmio_clk
	um: Silence lockdep complaint about mmap_sem
	powerpc/4xx/uic: clear pending interrupt after irq type/pol change
	RDMA/i40iw: Set queue pair state when being queried
	serial: sh-sci: Terminate TX DMA during buffer flushing
	serial: sh-sci: Fix TX DMA buffer flushing and workqueue races
	kallsyms: exclude kasan local symbols on s390
	perf test mmap-thread-lookup: Initialize variable to suppress memory sanitizer warning
	RDMA/rxe: Fill in wc byte_len with IB_WC_RECV_RDMA_WITH_IMM
	powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h
	f2fs: avoid out-of-range memory access
	mailbox: handle failed named mailbox channel request
	powerpc/eeh: Handle hugepages in ioremap space
	sh: prevent warnings when using iounmap
	mm/kmemleak.c: fix check for softirq context
	9p: pass the correct prototype to read_cache_page
	mm/mmu_notifier: use hlist_add_head_rcu()
	locking/lockdep: Fix lock used or unused stats error
	locking/lockdep: Hide unused 'class' variable
	usb: wusbcore: fix unbalanced get/put cluster_id
	usb: pci-quirks: Correct AMD PLL quirk detection
	x86/sysfb_efi: Add quirks for some devices with swapped width and height
	x86/speculation/mds: Apply more accurate check on hypervisor platform
	hpet: Fix division by zero in hpet_time_div()
	ALSA: line6: Fix wrong altsetting for LINE6_PODHD500_1
	ALSA: hda - Add a conexant codec entry to let mute led work
	powerpc/tm: Fix oops on sigreturn on systems without TM
	access: avoid the RCU grace period for the temporary subjective credentials
	ipv6: check sk sk_type and protocol early in ip_mroute_set/getsockopt
	tcp: reset sk_send_head in tcp_write_queue_purge
	arm64: dts: marvell: Fix A37xx UART0 register size
	i2c: qup: fixed releasing dma without flush operation completion
	arm64: compat: Provide definition for COMPAT_SIGMINSTKSZ
	ISDN: hfcsusb: checking idx of ep configuration
	media: au0828: fix null dereference in error path
	media: cpia2_usb: first wake up, then free in disconnect
	media: radio-raremono: change devm_k*alloc to k*alloc
	Bluetooth: hci_uart: check for missing tty operations
	sched/fair: Don't free p->numa_faults with concurrent readers
	drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl
	ceph: hold i_ceph_lock when removing caps for freeing inode
	Linux 4.9.187

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-08-04 09:50:32 +02:00
Jann Horn
837ffc9723 sched/fair: Don't free p->numa_faults with concurrent readers
commit 16d51a590a8ce3befb1308e0e7ab77f3b661af33 upstream.

When going through execve(), zero out the NUMA fault statistics instead of
freeing them.

During execve, the task is reachable through procfs and the scheduler. A
concurrent /proc/*/sched reader can read data from a freed ->numa_faults
allocation (confirmed by KASAN) and write it back to userspace.
I believe that it would also be possible for a use-after-free read to occur
through a race between a NUMA fault and execve(): task_numa_fault() can
lead to task_numa_compare(), which invokes task_weight() on the currently
running task of a different CPU.

Another way to fix this would be to make ->numa_faults RCU-managed or add
extra locking, but it seems easier to wipe the NUMA fault statistics on
execve.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Fixes: 82727018b0 ("sched/numa: Call task_numa_free() from do_execve()")
Link: https://lkml.kernel.org/r/20190716152047.14424-1-jannh@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-04 09:33:45 +02:00
Linus Torvalds
50810015e0 access: avoid the RCU grace period for the temporary subjective credentials
commit d7852fbd0f0423937fa287a598bfde188bb68c22 upstream.

It turns out that 'access()' (and 'faccessat()') can cause a lot of RCU
work because it installs a temporary credential that gets allocated and
freed for each system call.

The allocation and freeing overhead is mostly benign, but because
credentials can be accessed under the RCU read lock, the freeing
involves a RCU grace period.

Which is not a huge deal normally, but if you have a lot of access()
calls, this causes a fair amount of seconday damage: instead of having a
nice alloc/free patterns that hits in hot per-CPU slab caches, you have
all those delayed free's, and on big machines with hundreds of cores,
the RCU overhead can end up being enormous.

But it turns out that all of this is entirely unnecessary.  Exactly
because access() only installs the credential as the thread-local
subjective credential, the temporary cred pointer doesn't actually need
to be RCU free'd at all.  Once we're done using it, we can just free it
synchronously and avoid all the RCU overhead.

So add a 'non_rcu' flag to 'struct cred', which can be set by users that
know they only use it in non-RCU context (there are other potential
users for this).  We can make it a union with the rcu freeing list head
that we need for the RCU case, so this doesn't need any extra storage.

Note that this also makes 'get_current_cred()' clear the new non_rcu
flag, in case we have filesystems that take a long-term reference to the
cred and then expect the RCU delayed freeing afterwards.  It's not
entirely clear that this is required, but it makes for clear semantics:
the subjective cred remains non-RCU as long as you only access it
synchronously using the thread-local accessors, but you _can_ use it as
a generic cred if you want to.

It is possible that we should just remove the whole RCU markings for
->cred entirely.  Only ->real_cred is really supposed to be accessed
through RCU, and the long-term cred copies that nfs uses might want to
explicitly re-enable RCU freeing if required, rather than have
get_current_cred() do it implicitly.

But this is a "minimal semantic changes" change for the immediate
problem.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jan Glauber <jglauber@marvell.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Jayachandran Chandrasekharan Nair <jnair@marvell.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-04 09:33:43 +02:00
Andrey Ryabinin
4b5d4bdfd1 compiler.h: Add read_word_at_a_time() function.
[ Upstream commit 7f1e541fc8d57a143dd5df1d0a1276046e08c083 ]

Sometimes we know that it's safe to do potentially out-of-bounds access
because we know it won't cross a page boundary.  Still, KASAN will
report this as a bug.

Add read_word_at_a_time() function which is supposed to be used in such
cases.  In read_word_at_a_time() KASAN performs relaxed check - only the
first byte of access is validated.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-04 09:33:32 +02:00
Andrey Ryabinin
229b670e66 compiler.h, kasan: Avoid duplicating __read_once_size_nocheck()
[ Upstream commit bdb5ac801af3d81d36732c2f640d6a1d3df83826 ]

Instead of having two identical __read_once_size_nocheck() functions
with different attributes, consolidate all the difference in new macro
__no_kasan_or_inline and use it. No functional changes.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-04 09:33:32 +02:00
Marek Szyprowski
df5b05868d clocksource/drivers/exynos_mct: Increase priority over ARM arch timer
[ Upstream commit 6282edb72bed5324352522d732080d4c1b9dfed6 ]

Exynos SoCs based on CA7/CA15 have 2 timer interfaces: custom Exynos MCT
(Multi Core Timer) and standard ARM Architected Timers.

There are use cases, where both timer interfaces are used simultanously.
One of such examples is using Exynos MCT for the main system timer and
ARM Architected Timers for the KVM and virtualized guests (KVM requires
arch timers).

Exynos Multi-Core Timer driver (exynos_mct) must be however started
before ARM Architected Timers (arch_timer), because they both share some
common hardware blocks (global system counter) and turning on MCT is
needed to get ARM Architected Timer working properly.

To ensure selecting Exynos MCT as the main system timer, increase MCT
timer rating. To ensure proper starting order of both timers during
suspend/resume cycle, increase MCT hotplug priority over ARM Archictected
Timers.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-04 09:33:22 +02:00
Waiman Long
8151383a17 rcu: Force inlining of rcu_read_lock()
[ Upstream commit 6da9f775175e516fc7229ceaa9b54f8f56aa7924 ]

When debugging options are turned on, the rcu_read_lock() function
might not be inlined. This results in lockdep's print_lock() function
printing "rcu_read_lock+0x0/0x70" instead of rcu_read_lock()'s caller.
For example:

[   10.579995] =============================
[   10.584033] WARNING: suspicious RCU usage
[   10.588074] 4.18.0.memcg_v2+ #1 Not tainted
[   10.593162] -----------------------------
[   10.597203] include/linux/rcupdate.h:281 Illegal context switch in
RCU read-side critical section!
[   10.606220]
[   10.606220] other info that might help us debug this:
[   10.606220]
[   10.614280]
[   10.614280] rcu_scheduler_active = 2, debug_locks = 1
[   10.620853] 3 locks held by systemd/1:
[   10.624632]  #0: (____ptrval____) (&type->i_mutex_dir_key#5){.+.+}, at: lookup_slow+0x42/0x70
[   10.633232]  #1: (____ptrval____) (rcu_read_lock){....}, at: rcu_read_lock+0x0/0x70
[   10.640954]  #2: (____ptrval____) (rcu_read_lock){....}, at: rcu_read_lock+0x0/0x70

These "rcu_read_lock+0x0/0x70" strings are not providing any useful
information.  This commit therefore forces inlining of the rcu_read_lock()
function so that rcu_read_lock()'s caller is instead shown.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-08-04 09:33:19 +02:00
Greg Kroah-Hartman
83cf3cfdb2 Merge 4.9.186 into android-4.9-q
Changes in 4.9.186
	crypto: talitos - rename alternative AEAD algos.
	Input: elantech - enable middle button support on 2 ThinkPads
	samples, bpf: fix to change the buffer size for read()
	staging:iio:ad7150: fix threshold mode config bit
	mac80211: mesh: fix RCU warning
	mac80211: free peer keys before vif down in mesh
	mwifiex: Fix possible buffer overflows at parsing bss descriptor
	netfilter: ipv6: nf_defrag: fix leakage of unqueued fragments
	netfilter: ipv6: nf_defrag: accept duplicate fragments again
	dt-bindings: can: mcp251x: add mcp25625 support
	can: mcp251x: add support for mcp25625
	Input: imx_keypad - make sure keyboard can always wake up system
	KVM: arm/arm64: vgic: Fix kvm_device leak in vgic_its_destroy
	mlxsw: spectrum: Disallow prio-tagged packets when PVID is removed
	ARM: davinci: da850-evm: call regulator_has_full_constraints()
	ARM: davinci: da8xx: specify dma_coherent_mask for lcdc
	mac80211: only warn once on chanctx_conf being NULL
	md: fix for divide error in status_resync
	bnx2x: Check if transceiver implements DDM before access
	ip6_tunnel: allow not to count pkts on tstats by passing dev as NULL
	net :sunrpc :clnt :Fix xps refcount imbalance on the error path
	udf: Fix incorrect final NOT_ALLOCATED (hole) extent length
	x86/ptrace: Fix possible spectre-v1 in ptrace_get_debugreg()
	x86/tls: Fix possible spectre-v1 in do_get_thread_area()
	mwifiex: Abort at too short BSS descriptor element
	mwifiex: Fix heap overflow in mwifiex_uap_parse_tail_ies()
	fscrypt: don't set policy for a dead directory
	mwifiex: Don't abort on small, spec-compliant vendor IEs
	USB: serial: ftdi_sio: add ID for isodebug v1
	USB: serial: option: add support for GosunCn ME3630 RNDIS mode
	Revert "serial: 8250: Don't service RX FIFO if interrupts are disabled"
	p54usb: Fix race between disconnect and firmware loading
	usb: gadget: ether: Fix race between gether_disconnect and rx_submit
	usb: renesas_usbhs: add a workaround for a race condition of workqueue
	staging: comedi: dt282x: fix a null pointer deref on interrupt
	staging: comedi: amplc_pci230: fix null pointer deref on interrupt
	carl9170: fix misuse of device driver API
	VMCI: Fix integer overflow in VMCI handle arrays
	MIPS: Remove superfluous check for __linux__
	Revert "e1000e: fix cyclic resets at link up with active tx"
	e1000e: start network tx queue only when link is up
	nilfs2: do not use unexported cpu_to_le32()/le32_to_cpu() in uapi header
	arm64: crypto: remove accidentally backported files
	perf/core: Fix perf_sample_regs_user() mm check
	ARM: omap2: remove incorrect __init annotation
	be2net: fix link failure after ethtool offline test
	ppp: mppe: Add softdep to arc4
	sis900: fix TX completion
	ARM: dts: imx6ul: fix PWM[1-4] interrupts
	dm verity: use message limit for data block corruption message
	ARC: hide unused function unw_hdr_alloc
	s390: fix stfle zero padding
	s390/qdio: (re-)initialize tiqdio list entries
	s390/qdio: don't touch the dsci in tiqdio_add_input_queues()
	Linux 4.9.186

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-07-22 15:07:58 +02:00
Vishnu DASA
6f56992a4e VMCI: Fix integer overflow in VMCI handle arrays
commit 1c2eb5b2853c9f513690ba6b71072d8eb65da16a upstream.

The VMCI handle array has an integer overflow in
vmci_handle_arr_append_entry when it tries to expand the array. This can be
triggered from a guest, since the doorbell link hypercall doesn't impose a
limit on the number of doorbell handles that a VM can create in the
hypervisor, and these handles are stored in a handle array.

In this change, we introduce a mandatory max capacity for handle
arrays/lists to avoid excessive memory usage.

Signed-off-by: Vishnu Dasa <vdasa@vmware.com>
Reviewed-by: Adit Ranadive <aditr@vmware.com>
Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-21 09:06:03 +02:00
Greg Kroah-Hartman
39eed54804 Merge 4.9.185 into android-4.9-q
Changes in 4.9.185
	tracing: Silence GCC 9 array bounds warning
	gcc-9: silence 'address-of-packed-member' warning
	scsi: ufs: Avoid runtime suspend possibly being blocked forever
	usb: chipidea: udc: workaround for endpoint conflict issue
	IB/hfi1: Silence txreq allocation warnings
	Input: uinput - add compat ioctl number translation for UI_*_FF_UPLOAD
	apparmor: enforce nullbyte at end of tag string
	ARC: fix build warnings with !CONFIG_KPROBES
	parport: Fix mem leak in parport_register_dev_model
	parisc: Fix compiler warnings in float emulation code
	IB/rdmavt: Fix alloc_qpn() WARN_ON()
	IB/hfi1: Insure freeze_work work_struct is canceled on shutdown
	IB/{qib, hfi1, rdmavt}: Correct ibv_devinfo max_mr value
	MIPS: uprobes: remove set but not used variable 'epc'
	net: dsa: mv88e6xxx: avoid error message on remove from VLAN 0
	net: hns: Fix loopback test failed at copper ports
	sparc: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD
	net: ethernet: mediatek: Use hw_feature to judge if HWLRO is supported
	net: ethernet: mediatek: Use NET_IP_ALIGN to judge if HW RX_2BYTE_OFFSET is enabled
	drm/arm/hdlcd: Allow a bit of clock tolerance
	scripts/checkstack.pl: Fix arm64 wrong or unknown architecture
	scsi: ufs: Check that space was properly alloced in copy_query_response
	s390/qeth: fix VLAN attribute in bridge_hostnotify udev event
	hwmon: (pmbus/core) Treat parameters as paged if on multiple pages
	nvme: Fix u32 overflow in the number of namespace list calculation
	btrfs: start readahead also in seed devices
	can: flexcan: fix timeout when set small bitrate
	can: purge socket error queue on sock destruct
	powerpc/bpf: use unsigned division instruction for 64-bit operations
	ARM: imx: cpuidle-imx6sx: Restrict the SW2ISO increase to i.MX6SX
	Bluetooth: Align minimum encryption key size for LE and BR/EDR connections
	Bluetooth: Fix regression with minimum encryption key size alignment
	cfg80211: fix memory leak of wiphy device name
	mac80211: drop robust management frames from unknown TA
	mac80211: Do not use stack memory with scatterlist for GMAC
	IB/hfi1: Avoid hardlockup with flushlist_lock
	perf ui helpline: Use strlcpy() as a shorter form of strncpy() + explicit set nul
	perf help: Remove needless use of strncpy()
	perf header: Fix unchecked usage of strncpy()
	9p/rdma: do not disconnect on down_interruptible EAGAIN
	9p: acl: fix uninitialized iattr access
	9p/rdma: remove useless check in cm_event_handler
	9p: p9dirent_read: check network-provided name length
	net/9p: include trans_common.h to fix missing prototype warning.
	fs/proc/array.c: allow reporting eip/esp for all coredumping threads
	fs/binfmt_flat.c: make load_flat_shared_library() work
	mm/page_idle.c: fix oops because end_pfn is larger than max_pfn
	scsi: vmw_pscsi: Fix use-after-free in pvscsi_queue_lck()
	x86/speculation: Allow guests to use SSBD even if host does not
	NFS/flexfiles: Use the correct TCP timeout for flexfiles I/O
	cpu/speculation: Warn on unsupported mitigations= parameter
	af_packet: Block execution of tasks waiting for transmit to complete in AF_PACKET
	net: stmmac: fixed new system time seconds value calculation
	sctp: change to hold sk after auth shkey is created successfully
	tipc: change to use register_pernet_device
	tipc: check msg->req data len in tipc_nl_compat_bearer_disable
	tun: wake up waitqueues after IFF_UP is set
	team: Always enable vlan tx offload
	bonding: Always enable vlan tx offload
	ipv4: Use return value of inet_iif() for __raw_v4_lookup in the while loop
	net: check before dereferencing netdev_ops during busy poll
	bpf: udp: Avoid calling reuseport's bpf_prog from udp_gro
	bpf: udp: ipv6: Avoid running reuseport's bpf_prog from __udp6_lib_err
	tipc: pass tunnel dev as NULL to udp_tunnel(6)_xmit_skb
	Bluetooth: Fix faulty expression for minimum encryption key size check
	ASoC : cs4265 : readable register too low
	ASoC: soc-pcm: BE dai needs prepare when pause release after resume
	spi: bitbang: Fix NULL pointer dereference in spi_unregister_master
	drm/mediatek: fix unbind functions
	ASoC: max98090: remove 24-bit format support if RJ is 0
	usb: gadget: fusb300_udc: Fix memory leak of fusb300->ep[i]
	usb: gadget: udc: lpc32xx: allocate descriptor with GFP_ATOMIC
	scsi: hpsa: correct ioaccel2 chaining
	scripts/decode_stacktrace.sh: prefix addr2line with $CROSS_COMPILE
	mm/mlock.c: change count_mm_mlocked_page_nr return type
	MIPS: math-emu: do not use bools for arithmetic
	MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn_send()
	mfd: omap-usb-tll: Fix register offsets
	ARC: fix allnoconfig build warning
	bug.h: work around GCC PR82365 in BUG()
	ARC: handle gcc generated __builtin_trap for older compiler
	clk: sunxi: fix uninitialized access
	KVM: x86: degrade WARN to pr_warn_ratelimited
	drm/i915/dmc: protect against reading random memory
	MIPS: Workaround GCC __builtin_unreachable reordering bug
	ptrace: Fix ->ptracer_cred handling for PTRACE_TRACEME
	crypto: user - prevent operating on larval algorithms
	ALSA: seq: fix incorrect order of dest_client/dest_ports arguments
	ALSA: firewire-lib/fireworks: fix miss detection of received MIDI messages
	ALSA: line6: Fix write on zero-sized buffer
	ALSA: usb-audio: fix sign unintended sign extension on left shifts
	lib/mpi: Fix karactx leak in mpi_powm
	drm/imx: notify drm core before sending event during crtc disable
	drm/imx: only send event on crtc disable if kept disabled
	btrfs: Ensure replaced device doesn't have pending chunk allocation
	tty: rocket: fix incorrect forward declaration of 'rp_init()'
	arm64, vdso: Define vdso_{start,end} as array
	KVM: LAPIC: Fix pending interrupt in IRR blocked by software disable LAPIC
	IB/hfi1: Close PSM sdma_progress sleep window
	MIPS: Add missing EHB in mtc0 -> mfc0 sequence.
	dmaengine: imx-sdma: remove BD_INTR for channel0
	arm64: kaslr: keep modules inside module region when KASAN is enabled
	Linux 4.9.185

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-07-10 12:32:12 +02:00
Arnd Bergmann
074d0aaec0 bug.h: work around GCC PR82365 in BUG()
[ Upstream commit 173a3efd3edb2ef6ef07471397c5f542a360e9c1 ]

Looking at functions with large stack frames across all architectures
led me discovering that BUG() suffers from the same problem as
fortify_panic(), which I've added a workaround for already.

In short, variables that go out of scope by calling a noreturn function
or __builtin_unreachable() keep using stack space in functions
afterwards.

A workaround that was identified is to insert an empty assembler
statement just before calling the function that doesn't return.  I'm
adding a macro "barrier_before_unreachable()" to document this, and
insert calls to that in all instances of BUG() that currently suffer
from this problem.

The files that saw the largest change from this had these frame sizes
before, and much less with my patch:

  fs/ext4/inode.c:82:1: warning: the frame size of 1672 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/namei.c:434:1: warning: the frame size of 904 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/super.c:2279:1: warning: the frame size of 1160 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/xattr.c:146:1: warning: the frame size of 1168 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/f2fs/inode.c:152:1: warning: the frame size of 1424 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:1195:1: warning: the frame size of 1068 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:395:1: warning: the frame size of 1084 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:298:1: warning: the frame size of 928 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:418:1: warning: the frame size of 908 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_lblcr.c:718:1: warning: the frame size of 960 bytes is larger than 800 bytes [-Wframe-larger-than=]
  drivers/net/xen-netback/netback.c:1500:1: warning: the frame size of 1088 bytes is larger than 800 bytes [-Wframe-larger-than=]

In case of ARC and CRIS, it turns out that the BUG() implementation
actually does return (or at least the compiler thinks it does),
resulting in lots of warnings about uninitialized variable use and
leaving noreturn functions, such as:

  block/cfq-iosched.c: In function 'cfq_async_queue_prio':
  block/cfq-iosched.c:3804:1: error: control reaches end of non-void function [-Werror=return-type]
  include/linux/dmaengine.h: In function 'dma_maxpq':
  include/linux/dmaengine.h:1123:1: error: control reaches end of non-void function [-Werror=return-type]

This makes them call __builtin_trap() instead, which should normally
dump the stack and kill the current process, like some of the other
architectures already do.

I tried adding barrier_before_unreachable() to panic() and
fortify_panic() as well, but that had very little effect, so I'm not
submitting that patch.

Vineet said:

: For ARC, it is double win.
:
: 1. Fixes 3 -Wreturn-type warnings
:
: | ../net/core/ethtool.c:311:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../kernel/sched/core.c:3246:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../include/linux/sunrpc/svc_xprt.h:180:1: warning: control reaches end of
: non-void function [-Wreturn-type]
:
: 2.  bloat-o-meter reports code size improvements as gcc elides the
:    generated code for stack return.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
Link: http://lkml.kernel.org/r/20171219114112.939391-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Vineet Gupta <vgupta@synopsys.com>	[arch/arc]
Tested-by: Vineet Gupta <vgupta@synopsys.com>	[arch/arc]
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christopher Li <sparse@chrisli.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[removed cris chunks - gregkh]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-10 09:55:44 +02:00
Greg Kroah-Hartman
a0b21f86b2 Merge 4.9.183 into android-4.9-q
Changes in 4.9.183
	rapidio: fix a NULL pointer dereference when create_workqueue() fails
	fs/fat/file.c: issue flush after the writeback of FAT
	sysctl: return -EINVAL if val violates minmax
	ipc: prevent lockup on alloc_msg and free_msg
	ARM: prevent tracing IPI_CPU_BACKTRACE
	hugetlbfs: on restore reserve error path retain subpool reservation
	mem-hotplug: fix node spanned pages when we have a node with only ZONE_MOVABLE
	mm/cma.c: fix crash on CMA allocation if bitmap allocation fails
	mm/cma_debug.c: fix the break condition in cma_maxchunk_get()
	mm/slab.c: fix an infinite loop in leaks_show()
	kernel/sys.c: prctl: fix false positive in validate_prctl_map()
	drivers: thermal: tsens: Don't print error message on -EPROBE_DEFER
	mfd: tps65912-spi: Add missing of table registration
	mfd: intel-lpss: Set the device in reset state when init
	mfd: twl6040: Fix device init errors for ACCCTL register
	perf/x86/intel: Allow PEBS multi-entry in watermark mode
	drm/bridge: adv7511: Fix low refresh rate selection
	objtool: Don't use ignore flag for fake jumps
	pwm: meson: Use the spin-lock only to protect register modifications
	ntp: Allow TAI-UTC offset to be set to zero
	f2fs: fix to avoid panic in do_recover_data()
	f2fs: fix to clear dirty inode in error path of f2fs_iget()
	f2fs: fix to do sanity check on valid block count of segment
	configfs: fix possible use-after-free in configfs_register_group
	uml: fix a boot splat wrt use of cpu_all_mask
	watchdog: imx2_wdt: Fix set_timeout for big timeout values
	watchdog: fix compile time error of pretimeout governors
	iommu/vt-d: Set intel_iommu_gfx_mapped correctly
	ALSA: hda - Register irq handler after the chip initialization
	nvmem: core: fix read buffer in place
	fuse: retrieve: cap requested size to negotiated max_write
	nfsd: allow fh_want_write to be called twice
	x86/PCI: Fix PCI IRQ routing table memory leak
	platform/chrome: cros_ec_proto: check for NULL transfer function
	soc: mediatek: pwrap: Zero initialize rdata in pwrap_init_cipher
	clk: rockchip: Turn on "aclk_dmac1" for suspend on rk3288
	ARM: dts: imx6sx: Specify IMX6SX_CLK_IPG as "ahb" clock to SDMA
	ARM: dts: imx7d: Specify IMX7D_CLK_IPG as "ipg" clock to SDMA
	ARM: dts: imx6ul: Specify IMX6UL_CLK_IPG as "ipg" clock to SDMA
	ARM: dts: imx6sx: Specify IMX6SX_CLK_IPG as "ipg" clock to SDMA
	ARM: dts: imx6qdl: Specify IMX6QDL_CLK_IPG as "ipg" clock to SDMA
	PCI: rpadlpar: Fix leaked device_node references in add/remove paths
	platform/x86: intel_pmc_ipc: adding error handling
	PCI: rcar: Fix a potential NULL pointer dereference
	PCI: rcar: Fix 64bit MSI message address handling
	video: hgafb: fix potential NULL pointer dereference
	video: imsttfb: fix potential NULL pointer dereferences
	PCI: xilinx: Check for __get_free_pages() failure
	gpio: gpio-omap: add check for off wake capable gpios
	dmaengine: idma64: Use actual device for DMA transfers
	pwm: tiehrpwm: Update shadow register for disabling PWMs
	ARM: dts: exynos: Always enable necessary APIO_1V8 and ABB_1V8 regulators on Arndale Octa
	pwm: Fix deadlock warning when removing PWM device
	ARM: exynos: Fix undefined instruction during Exynos5422 resume
	Revert "Bluetooth: Align minimum encryption key size for LE and BR/EDR connections"
	ALSA: seq: Cover unsubscribe_port() in list_mutex
	ALSA: oxfw: allow PCM capture for Stanton SCS.1m
	libata: Extend quirks for the ST1000LM024 drives with NOLPM quirk
	mm/list_lru.c: fix memory leak in __memcg_init_list_lru_node
	fs/ocfs2: fix race in ocfs2_dentry_attach_lock()
	signal/ptrace: Don't leak unitialized kernel memory with PTRACE_PEEK_SIGINFO
	ptrace: restore smp_rmb() in __ptrace_may_access()
	media: v4l2-ioctl: clear fields in s_parm
	i2c: acorn: fix i2c warning
	bcache: fix stack corruption by PRECEDING_KEY()
	cgroup: Use css_tryget() instead of css_tryget_online() in task_get_css()
	ASoC: cs42xx8: Add regcache mask dirty
	ASoC: fsl_asrc: Fix the issue about unsupported rate
	x86/uaccess, kcov: Disable stack protector
	ALSA: seq: Protect in-kernel ioctl calls with mutex
	ALSA: seq: Fix race of get-subscription call vs port-delete ioctls
	Revert "ALSA: seq: Protect in-kernel ioctl calls with mutex"
	Drivers: misc: fix out-of-bounds access in function param_set_kgdbts_var
	scsi: lpfc: add check for loss of ndlp when sending RRQ
	arm64/mm: Inhibit huge-vmap with ptdump
	scsi: bnx2fc: fix incorrect cast to u64 on shift operation
	selftests/timers: Add missing fflush(stdout) calls
	usbnet: ipheth: fix racing condition
	KVM: x86/pmu: do not mask the value that is written to fixed PMUs
	KVM: s390: fix memory slot handling for KVM_SET_USER_MEMORY_REGION
	drm/vmwgfx: integer underflow in vmw_cmd_dx_set_shader() leading to an invalid read
	drm/vmwgfx: NULL pointer dereference from vmw_cmd_dx_view_define()
	usb: dwc2: Fix DMA cache alignment issues
	USB: Fix chipmunk-like voice when using Logitech C270 for recording audio.
	USB: usb-storage: Add new ID to ums-realtek
	USB: serial: pl2303: add Allied Telesis VT-Kit3
	USB: serial: option: add support for Simcom SIM7500/SIM7600 RNDIS mode
	USB: serial: option: add Telit 0x1260 and 0x1261 compositions
	rtc: pcf8523: don't return invalid date when battery is low
	ax25: fix inconsistent lock state in ax25_destroy_timer
	be2net: Fix number of Rx queues used for flow hashing
	ipv6: flowlabel: fl6_sock_lookup() must use atomic_inc_not_zero
	lapb: fixed leak of control-blocks.
	neigh: fix use-after-free read in pneigh_get_next
	sunhv: Fix device naming inconsistency between sunhv_console and sunhv_reg
	Revert "staging: vc04_services: prevent integer overflow in create_pagelist()"
	perf/x86/intel/ds: Fix EVENT vs. UEVENT PEBS constraints
	selftests: netfilter: missing error check when setting up veth interface
	mISDN: make sure device name is NUL terminated
	x86/CPU/AMD: Don't force the CPB cap when running under a hypervisor
	perf/ring_buffer: Fix exposing a temporarily decreased data_head
	perf/ring_buffer: Add ordering to rb->nest increment
	gpio: fix gpio-adp5588 build errors
	net: tulip: de4x5: Drop redundant MODULE_DEVICE_TABLE()
	i2c: dev: fix potential memory leak in i2cdev_ioctl_rdwr
	configfs: Fix use-after-free when accessing sd->s_dentry
	perf data: Fix 'strncat may truncate' build failure with recent gcc
	perf record: Fix s390 missing module symbol and warning for non-root users
	ia64: fix build errors by exporting paddr_to_nid()
	KVM: PPC: Book3S: Use new mutex to synchronize access to rtas token list
	KVM: PPC: Book3S HV: Don't take kvm->lock around kvm_for_each_vcpu
	net: sh_eth: fix mdio access in sh_eth_close() for R-Car Gen2 and RZ/A1 SoCs
	scsi: libcxgbi: add a check for NULL pointer in cxgbi_check_route()
	scsi: smartpqi: properly set both the DMA mask and the coherent DMA mask
	scsi: libsas: delete sas port if expander discover failed
	mlxsw: spectrum: Prevent force of 56G
	Abort file_remove_privs() for non-reg. files
	Linux 4.9.183

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-06-22 08:56:18 +02:00
Tejun Heo
df260f7a03 cgroup: Use css_tryget() instead of css_tryget_online() in task_get_css()
commit 18fa84a2db0e15b02baa5d94bdb5bd509175d2f6 upstream.

A PF_EXITING task can stay associated with an offline css.  If such
task calls task_get_css(), it can get stuck indefinitely.  This can be
triggered by BSD process accounting which writes to a file with
PF_EXITING set when racing against memcg disable as in the backtrace
at the end.

After this change, task_get_css() may return a css which was already
offline when the function was called.  None of the existing users are
affected by this change.

  INFO: rcu_sched self-detected stall on CPU
  INFO: rcu_sched detected stalls on CPUs/tasks:
  ...
  NMI backtrace for cpu 0
  ...
  Call Trace:
   <IRQ>
   dump_stack+0x46/0x68
   nmi_cpu_backtrace.cold.2+0x13/0x57
   nmi_trigger_cpumask_backtrace+0xba/0xca
   rcu_dump_cpu_stacks+0x9e/0xce
   rcu_check_callbacks.cold.74+0x2af/0x433
   update_process_times+0x28/0x60
   tick_sched_timer+0x34/0x70
   __hrtimer_run_queues+0xee/0x250
   hrtimer_interrupt+0xf4/0x210
   smp_apic_timer_interrupt+0x56/0x110
   apic_timer_interrupt+0xf/0x20
   </IRQ>
  RIP: 0010:balance_dirty_pages_ratelimited+0x28f/0x3d0
  ...
   btrfs_file_write_iter+0x31b/0x563
   __vfs_write+0xfa/0x140
   __kernel_write+0x4f/0x100
   do_acct_process+0x495/0x580
   acct_process+0xb9/0xdb
   do_exit+0x748/0xa00
   do_group_exit+0x3a/0xa0
   get_signal+0x254/0x560
   do_signal+0x23/0x5c0
   exit_to_usermode_loop+0x5d/0xa0
   prepare_exit_to_usermode+0x53/0x80
   retint_user+0x8/0x8

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org # v4.2+
Fixes: ec438699a9 ("cgroup, block: implement task_get_css() and use it in bio_associate_current()")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-22 08:17:19 +02:00
Phong Hoang
d7650c74b6 pwm: Fix deadlock warning when removing PWM device
[ Upstream commit 347ab9480313737c0f1aaa08e8f2e1a791235535 ]

This patch fixes deadlock warning if removing PWM device
when CONFIG_PROVE_LOCKING is enabled.

This issue can be reproceduced by the following steps on
the R-Car H3 Salvator-X board if the backlight is disabled:

 # cd /sys/class/pwm/pwmchip0
 # echo 0 > export
 # ls
 device  export  npwm  power  pwm0  subsystem  uevent  unexport
 # cd device/driver
 # ls
 bind  e6e31000.pwm  uevent  unbind
 # echo e6e31000.pwm > unbind

[   87.659974] ======================================================
[   87.666149] WARNING: possible circular locking dependency detected
[   87.672327] 5.0.0 #7 Not tainted
[   87.675549] ------------------------------------------------------
[   87.681723] bash/2986 is trying to acquire lock:
[   87.686337] 000000005ea0e178 (kn->count#58){++++}, at: kernfs_remove_by_name_ns+0x50/0xa0
[   87.694528]
[   87.694528] but task is already holding lock:
[   87.700353] 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.707405]
[   87.707405] which lock already depends on the new lock.
[   87.707405]
[   87.715574]
[   87.715574] the existing dependency chain (in reverse order) is:
[   87.723048]
[   87.723048] -> #1 (pwm_lock){+.+.}:
[   87.728017]        __mutex_lock+0x70/0x7e4
[   87.732108]        mutex_lock_nested+0x1c/0x24
[   87.736547]        pwm_request_from_chip.part.6+0x34/0x74
[   87.741940]        pwm_request_from_chip+0x20/0x40
[   87.746725]        export_store+0x6c/0x1f4
[   87.750820]        dev_attr_store+0x18/0x28
[   87.754998]        sysfs_kf_write+0x54/0x64
[   87.759175]        kernfs_fop_write+0xe4/0x1e8
[   87.763615]        __vfs_write+0x40/0x184
[   87.767619]        vfs_write+0xa8/0x19c
[   87.771448]        ksys_write+0x58/0xbc
[   87.775278]        __arm64_sys_write+0x18/0x20
[   87.779721]        el0_svc_common+0xd0/0x124
[   87.783986]        el0_svc_compat_handler+0x1c/0x24
[   87.788858]        el0_svc_compat+0x8/0x18
[   87.792947]
[   87.792947] -> #0 (kn->count#58){++++}:
[   87.798260]        lock_acquire+0xc4/0x22c
[   87.802353]        __kernfs_remove+0x258/0x2c4
[   87.806790]        kernfs_remove_by_name_ns+0x50/0xa0
[   87.811836]        remove_files.isra.1+0x38/0x78
[   87.816447]        sysfs_remove_group+0x48/0x98
[   87.820971]        sysfs_remove_groups+0x34/0x4c
[   87.825583]        device_remove_attrs+0x6c/0x7c
[   87.830197]        device_del+0x11c/0x33c
[   87.834201]        device_unregister+0x14/0x2c
[   87.838638]        pwmchip_sysfs_unexport+0x40/0x4c
[   87.843509]        pwmchip_remove+0xf4/0x13c
[   87.847773]        rcar_pwm_remove+0x28/0x34
[   87.852039]        platform_drv_remove+0x24/0x64
[   87.856651]        device_release_driver_internal+0x18c/0x21c
[   87.862391]        device_release_driver+0x14/0x1c
[   87.867175]        unbind_store+0xe0/0x124
[   87.871265]        drv_attr_store+0x20/0x30
[   87.875442]        sysfs_kf_write+0x54/0x64
[   87.879618]        kernfs_fop_write+0xe4/0x1e8
[   87.884055]        __vfs_write+0x40/0x184
[   87.888057]        vfs_write+0xa8/0x19c
[   87.891887]        ksys_write+0x58/0xbc
[   87.895716]        __arm64_sys_write+0x18/0x20
[   87.900154]        el0_svc_common+0xd0/0x124
[   87.904417]        el0_svc_compat_handler+0x1c/0x24
[   87.909289]        el0_svc_compat+0x8/0x18
[   87.913378]
[   87.913378] other info that might help us debug this:
[   87.913378]
[   87.921374]  Possible unsafe locking scenario:
[   87.921374]
[   87.927286]        CPU0                    CPU1
[   87.931808]        ----                    ----
[   87.936331]   lock(pwm_lock);
[   87.939293]                                lock(kn->count#58);
[   87.945120]                                lock(pwm_lock);
[   87.950599]   lock(kn->count#58);
[   87.953908]
[   87.953908]  *** DEADLOCK ***
[   87.953908]
[   87.959821] 4 locks held by bash/2986:
[   87.963563]  #0: 00000000ace7bc30 (sb_writers#6){.+.+}, at: vfs_write+0x188/0x19c
[   87.971044]  #1: 00000000287991b2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xb4/0x1e8
[   87.978872]  #2: 00000000f739d016 (&dev->mutex){....}, at: device_release_driver_internal+0x40/0x21c
[   87.988001]  #3: 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c
[   87.995481]
[   87.995481] stack backtrace:
[   87.999836] CPU: 0 PID: 2986 Comm: bash Not tainted 5.0.0 #7
[   88.005489] Hardware name: Renesas Salvator-X board based on r8a7795 ES1.x (DT)
[   88.012791] Call trace:
[   88.015235]  dump_backtrace+0x0/0x190
[   88.018891]  show_stack+0x14/0x1c
[   88.022204]  dump_stack+0xb0/0xec
[   88.025514]  print_circular_bug.isra.32+0x1d0/0x2e0
[   88.030385]  __lock_acquire+0x1318/0x1864
[   88.034388]  lock_acquire+0xc4/0x22c
[   88.037958]  __kernfs_remove+0x258/0x2c4
[   88.041874]  kernfs_remove_by_name_ns+0x50/0xa0
[   88.046398]  remove_files.isra.1+0x38/0x78
[   88.050487]  sysfs_remove_group+0x48/0x98
[   88.054490]  sysfs_remove_groups+0x34/0x4c
[   88.058580]  device_remove_attrs+0x6c/0x7c
[   88.062671]  device_del+0x11c/0x33c
[   88.066154]  device_unregister+0x14/0x2c
[   88.070070]  pwmchip_sysfs_unexport+0x40/0x4c
[   88.074421]  pwmchip_remove+0xf4/0x13c
[   88.078163]  rcar_pwm_remove+0x28/0x34
[   88.081906]  platform_drv_remove+0x24/0x64
[   88.085996]  device_release_driver_internal+0x18c/0x21c
[   88.091215]  device_release_driver+0x14/0x1c
[   88.095478]  unbind_store+0xe0/0x124
[   88.099048]  drv_attr_store+0x20/0x30
[   88.102704]  sysfs_kf_write+0x54/0x64
[   88.106359]  kernfs_fop_write+0xe4/0x1e8
[   88.110275]  __vfs_write+0x40/0x184
[   88.113757]  vfs_write+0xa8/0x19c
[   88.117065]  ksys_write+0x58/0xbc
[   88.120374]  __arm64_sys_write+0x18/0x20
[   88.124291]  el0_svc_common+0xd0/0x124
[   88.128034]  el0_svc_compat_handler+0x1c/0x24
[   88.132384]  el0_svc_compat+0x8/0x18

The sysfs unexport in pwmchip_remove() is completely asymmetric
to what we do in pwmchip_add_with_polarity() and commit 0733424c9b
("pwm: Unexport children before chip removal") is a strong indication
that this was wrong to begin with. We should just move
pwmchip_sysfs_unexport() where it belongs, which is right after
pwmchip_sysfs_unexport_children(). In that case, we do not need
separate functions anymore either.

We also really want to remove sysfs irrespective of whether or not
the chip will be removed as a result of pwmchip_remove(). We can only
assume that the driver will be gone after that, so we shouldn't leave
any dangling sysfs files around.

This warning disappears if we move pwmchip_sysfs_unexport() to
the top of pwmchip_remove(), pwmchip_sysfs_unexport_children().
That way it is also outside of the pwm_lock section, which indeed
doesn't seem to be needed.

Moving the pwmchip_sysfs_export() call outside of that section also
seems fine and it'd be perfectly symmetric with pwmchip_remove() again.

So, this patch fixes them.

Signed-off-by: Phong Hoang <phong.hoang.wz@renesas.com>
[shimoda: revise the commit log and code]
Fixes: 76abbdde2d ("pwm: Add sysfs interface")
Fixes: 0733424c9b ("pwm: Unexport children before chip removal")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Hoan Nguyen An <na-hoan@jinso.co.jp>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-22 08:17:17 +02:00
Greg Kroah-Hartman
8b83e43efb Merge 4.9.182 into android-4.9-q
Changes in 4.9.182
	tcp: reduce tcp_fastretrans_alert() verbosity
	tcp: limit payload size of sacked skbs
	tcp: tcp_fragment() should apply sane memory limits
	tcp: add tcp_min_snd_mss sysctl
	tcp: enforce tcp_min_snd_mss in tcp_mtu_probing()
	Linux 4.9.182

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-06-17 20:29:43 +02:00
Eric Dumazet
cc1b58ccb7 tcp: limit payload size of sacked skbs
commit 3b4929f65b0d8249f19a50245cd88ed1a2f78cff upstream.

Jonathan Looney reported that TCP can trigger the following crash
in tcp_shifted_skb() :

	BUG_ON(tcp_skb_pcount(skb) < pcount);

This can happen if the remote peer has advertized the smallest
MSS that linux TCP accepts : 48

An skb can hold 17 fragments, and each fragment can hold 32KB
on x86, or 64KB on PowerPC.

This means that the 16bit witdh of TCP_SKB_CB(skb)->tcp_gso_segs
can overflow.

Note that tcp_sendmsg() builds skbs with less than 64KB
of payload, so this problem needs SACK to be enabled.
SACK blocks allow TCP to coalesce multiple skbs in the retransmit
queue, thus filling the 17 fragments to maximal capacity.

CVE-2019-11477 -- u16 overflow of TCP_SKB_CB(skb)->tcp_gso_segs

Backport notes, provided by Joao Martins <joao.m.martins@oracle.com>

v4.15 or since commit 737ff314563 ("tcp: use sequence distance to
detect reordering") had switched from the packet-based FACK tracking and
switched to sequence-based.

v4.14 and older still have the old logic and hence on
tcp_skb_shift_data() needs to retain its original logic and have
@fack_count in sync. In other words, we keep the increment of pcount with
tcp_skb_pcount(skb) to later used that to update fack_count. To make it
more explicit we track the new skb that gets incremented to pcount in
@next_pcount, and we get to avoid the constant invocation of
tcp_skb_pcount(skb) all together.

Fixes: 832d11c5cd ("tcp: Try to restore large SKBs while SACK processing")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jonathan Looney <jtl@netflix.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Bruce Curtis <brucec@netflix.com>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-17 19:53:32 +02:00
Greg Kroah-Hartman
77161ce013 Merge 4.9.181 into android-4.9-q
Changes in 4.9.181
	ipv6: Consider sk_bound_dev_if when binding a raw socket to an address
	llc: fix skb leak in llc_build_and_send_ui_pkt()
	net: fec: fix the clk mismatch in failed_reset path
	net-gro: fix use-after-free read in napi_gro_frags()
	net: stmmac: fix reset gpio free missing
	usbnet: fix kernel crash after disconnect
	tipc: Avoid copying bytes beyond the supplied data
	bnxt_en: Fix aggregation buffer leak under OOM condition.
	ipv4/igmp: fix another memory leak in igmpv3_del_delrec()
	ipv4/igmp: fix build error if !CONFIG_IP_MULTICAST
	net: dsa: mv88e6xxx: fix handling of upper half of STATS_TYPE_PORT
	net: mvneta: Fix err code path of probe
	net: mvpp2: fix bad MVPP2_TXQ_SCHED_TOKEN_CNTR_REG queue value
	crypto: vmx - ghash: do nosimd fallback manually
	xen/pciback: Don't disable PCI_COMMAND on PCI device reset.
	Revert "tipc: fix modprobe tipc failed after switch order of device registration"
	tipc: fix modprobe tipc failed after switch order of device registration
	sparc64: Fix regression in non-hypervisor TLB flush xcall
	include/linux/bitops.h: sanitize rotate primitives
	xhci: update bounce buffer with correct sg num
	xhci: Use %zu for printing size_t type
	xhci: Convert xhci_handshake() to use readl_poll_timeout_atomic()
	usb: xhci: avoid null pointer deref when bos field is NULL
	usbip: usbip_host: fix BUG: sleeping function called from invalid context
	usbip: usbip_host: fix stub_dev lock context imbalance regression
	USB: Fix slab-out-of-bounds write in usb_get_bos_descriptor
	USB: sisusbvga: fix oops in error path of sisusb_probe
	USB: Add LPM quirk for Surface Dock GigE adapter
	USB: rio500: refuse more than one device at a time
	USB: rio500: fix memory leak in close after disconnect
	media: usb: siano: Fix general protection fault in smsusb
	media: usb: siano: Fix false-positive "uninitialized variable" warning
	media: smsusb: better handle optional alignment
	scsi: zfcp: fix missing zfcp_port reference put on -EBUSY from port_remove
	scsi: zfcp: fix to prevent port_remove with pure auto scan LUNs (only sdevs)
	Btrfs: fix race updating log root item during fsync
	powerpc/perf: Fix MMCRA corruption by bhrb_filter
	ALSA: hda/realtek - Set default power save node to 0
	drm/nouveau/i2c: Disable i2c bus access after ->fini()
	tty: serial: msm_serial: Fix XON/XOFF
	tty: max310x: Fix external crystal register setup
	memcg: make it work on sparse non-0-node systems
	kernel/signal.c: trace_signal_deliver when signal_group_exit
	docs: Fix conf.py for Sphinx 2.0
	staging: vc04_services: prevent integer overflow in create_pagelist()
	CIFS: cifs_read_allocate_pages: don't iterate through whole page array on ENOMEM
	gcc-plugins: Fix build failures under Darwin host
	drm/vmwgfx: Don't send drm sysfs hotplug events on initial master set
	brcmfmac: add length checks in scheduled scan result handler
	brcmfmac: assure SSID length from firmware is limited
	brcmfmac: add subtype check for event handling in data path
	binder: Replace "%p" with "%pK" for stable
	binder: replace "%p" with "%pK"
	fs: prevent page refcount overflow in pipe_buf_get
	mm, gup: remove broken VM_BUG_ON_PAGE compound check for hugepages
	mm, gup: ensure real head page is ref-counted when using hugepages
	mm: prevent get_user_pages() from overflowing page refcount
	mm: make page ref count overflow check tighter and more explicit
	Revert "x86/build: Move _etext to actual end of .text"
	efi/libstub: Unify command line param parsing
	media: uvcvideo: Fix uvc_alloc_entity() allocation alignment
	ethtool: fix potential userspace buffer overflow
	neighbor: Call __ipv4_neigh_lookup_noref in neigh_xmit
	net/mlx4_en: ethtool, Remove unsupported SFP EEPROM high pages query
	net: rds: fix memory leak in rds_ib_flush_mr_pool
	pktgen: do not sleep with the thread lock held.
	ipv6: fix EFAULT on sendto with icmpv6 and hdrincl
	ipv6: use READ_ONCE() for inet->hdrincl as in ipv4
	Revert "fib_rules: fix error in backport of e9919a24d302 ("fib_rules: return 0...")"
	Revert "fib_rules: return 0 directly if an exactly same rule exists when NLM_F_EXCL not supplied"
	rcu: locking and unlocking need to always be at least barriers
	parisc: Use implicit space register selection for loading the coherence index of I/O pdirs
	fuse: fallocate: fix return with locked inode
	x86/power: Fix 'nosmt' vs hibernation triple fault during resume
	MIPS: pistachio: Build uImage.gz by default
	Revert "MIPS: perf: ath79: Fix perfcount IRQ assignment"
	genwqe: Prevent an integer overflow in the ioctl
	drm/gma500/cdv: Check vbt config bits when detecting lvds panels
	drm/radeon: prefer lower reference dividers
	drm/i915: Fix I915_EXEC_RING_MASK
	TTY: serial_core, add ->install
	fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock
	fuse: Add FOPEN_STREAM to use stream_open()
	ipv4: Define __ipv4_neigh_lookup_noref when CONFIG_INET is disabled
	ethtool: check the return value of get_regs_len
	Linux 4.9.181

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-06-11 14:39:40 +02:00
Kirill Smelkov
9c829b6e3f fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock
commit 10dce8af34226d90fa56746a934f8da5dcdba3df upstream.

Commit 9c225f2655 ("vfs: atomic f_pos accesses as per POSIX") added
locking for file.f_pos access and in particular made concurrent read and
write not possible - now both those functions take f_pos lock for the
whole run, and so if e.g. a read is blocked waiting for data, write will
deadlock waiting for that read to complete.

This caused regression for stream-like files where previously read and
write could run simultaneously, but after that patch could not do so
anymore. See e.g. commit 581d21a2d02a ("xenbus: fix deadlock on writes
to /proc/xen/xenbus") which fixes such regression for particular case of
/proc/xen/xenbus.

The patch that added f_pos lock in 2014 did so to guarantee POSIX thread
safety for read/write/lseek and added the locking to file descriptors of
all regular files. In 2014 that thread-safety problem was not new as it
was already discussed earlier in 2006.

However even though 2006'th version of Linus's patch was adding f_pos
locking "only for files that are marked seekable with FMODE_LSEEK (thus
avoiding the stream-like objects like pipes and sockets)", the 2014
version - the one that actually made it into the tree as 9c225f2655 -
is doing so irregardless of whether a file is seekable or not.

See

    https://lore.kernel.org/lkml/53022DB1.4070805@gmail.com/
    https://lwn.net/Articles/180387
    https://lwn.net/Articles/180396

for historic context.

The reason that it did so is, probably, that there are many files that
are marked non-seekable, but e.g. their read implementation actually
depends on knowing current position to correctly handle the read. Some
examples:

	kernel/power/user.c		snapshot_read
	fs/debugfs/file.c		u32_array_read
	fs/fuse/control.c		fuse_conn_waiting_read + ...
	drivers/hwmon/asus_atk0110.c	atk_debugfs_ggrp_read
	arch/s390/hypfs/inode.c		hypfs_read_iter
	...

Despite that, many nonseekable_open users implement read and write with
pure stream semantics - they don't depend on passed ppos at all. And for
those cases where read could wait for something inside, it creates a
situation similar to xenbus - the write could be never made to go until
read is done, and read is waiting for some, potentially external, event,
for potentially unbounded time -> deadlock.

Besides xenbus, there are 14 such places in the kernel that I've found
with semantic patch (see below):

	drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write()
	drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write()
	drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write()
	drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write()
	net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write()
	drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write()
	drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write()
	drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write()
	net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write()
	drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write()
	drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write()
	drivers/input/misc/uinput.c:400:1-17: ERROR: uinput_fops: .read() can deadlock .write()
	drivers/infiniband/core/user_mad.c:985:7-23: ERROR: umad_fops: .read() can deadlock .write()
	drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write()

In addition to the cases above another regression caused by f_pos
locking is that now FUSE filesystems that implement open with
FOPEN_NONSEEKABLE flag, can no longer implement bidirectional
stream-like files - for the same reason as above e.g. read can deadlock
write locking on file.f_pos in the kernel.

FUSE's FOPEN_NONSEEKABLE was added in 2008 in a7c1b990f7 ("fuse:
implement nonseekable open") to support OSSPD. OSSPD implements /dev/dsp
in userspace with FOPEN_NONSEEKABLE flag, with corresponding read and
write routines not depending on current position at all, and with both
read and write being potentially blocking operations:

See

    https://github.com/libfuse/osspd
    https://lwn.net/Articles/308445

    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1406
    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1438-L1477
    https://github.com/libfuse/osspd/blob/14a9cff0/osspd.c#L1479-L1510

Corresponding libfuse example/test also describes FOPEN_NONSEEKABLE as
"somewhat pipe-like files ..." with read handler not using offset.
However that test implements only read without write and cannot exercise
the deadlock scenario:

    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L124-L131
    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L146-L163
    https://github.com/libfuse/libfuse/blob/fuse-3.4.2-3-ga1bff7d/example/poll.c#L209-L216

I've actually hit the read vs write deadlock for real while implementing
my FUSE filesystem where there is /head/watch file, for which open
creates separate bidirectional socket-like stream in between filesystem
and its user with both read and write being later performed
simultaneously. And there it is semantically not easy to split the
stream into two separate read-only and write-only channels:

    https://lab.nexedi.com/kirr/wendelin.core/blob/f13aa600/wcfs/wcfs.go#L88-169

Let's fix this regression. The plan is:

1. We can't change nonseekable_open to include &~FMODE_ATOMIC_POS -
   doing so would break many in-kernel nonseekable_open users which
   actually use ppos in read/write handlers.

2. Add stream_open() to kernel to open stream-like non-seekable file
   descriptors. Read and write on such file descriptors would never use
   nor change ppos. And with that property on stream-like files read and
   write will be running without taking f_pos lock - i.e. read and write
   could be running simultaneously.

3. With semantic patch search and convert to stream_open all in-kernel
   nonseekable_open users for which read and write actually do not
   depend on ppos and where there is no other methods in file_operations
   which assume @offset access.

4. Add FOPEN_STREAM to fs/fuse/ and open in-kernel file-descriptors via
   steam_open if that bit is present in filesystem open reply.

   It was tempting to change fs/fuse/ open handler to use stream_open
   instead of nonseekable_open on just FOPEN_NONSEEKABLE flags, but
   grepping through Debian codesearch shows users of FOPEN_NONSEEKABLE,
   and in particular GVFS which actually uses offset in its read and
   write handlers

	https://codesearch.debian.net/search?q=-%3Enonseekable+%3D
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1080
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1247-1346
	https://gitlab.gnome.org/GNOME/gvfs/blob/1.40.0-6-gcbc54396/client/gvfsfusedaemon.c#L1399-1481

   so if we would do such a change it will break a real user.

5. Add stream_open and FOPEN_STREAM handling to stable kernels starting
   from v3.14+ (the kernel where 9c225f2655 first appeared).

   This will allow to patch OSSPD and other FUSE filesystems that
   provide stream-like files to return FOPEN_STREAM | FOPEN_NONSEEKABLE
   in their open handler and this way avoid the deadlock on all kernel
   versions. This should work because fs/fuse/ ignores unknown open
   flags returned from a filesystem and so passing FOPEN_STREAM to a
   kernel that is not aware of this flag cannot hurt. In turn the kernel
   that is not aware of FOPEN_STREAM will be < v3.14 where just
   FOPEN_NONSEEKABLE is sufficient to implement streams without read vs
   write deadlock.

This patch adds stream_open, converts /proc/xen/xenbus to it and adds
semantic patch to automatically locate in-kernel places that are either
required to be converted due to read vs write deadlock, or that are just
safe to be converted because read and write do not use ppos and there
are no other funky methods in file_operations.

Regarding semantic patch I've verified each generated change manually -
that it is correct to convert - and each other nonseekable_open instance
left - that it is either not correct to convert there, or that it is not
converted due to current stream_open.cocci limitations.

The script also does not convert files that should be valid to convert,
but that currently have .llseek = noop_llseek or generic_file_llseek for
unknown reason despite file being opened with nonseekable_open (e.g.
drivers/input/mousedev.c)

Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Yongzhi Pan <panyongzhi@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Tejun Heo <tj@kernel.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Nikolaus Rath <Nikolaus@rath.org>
Cc: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:22:49 +02:00
Jiri Kosina
5bdc536ce6 x86/power: Fix 'nosmt' vs hibernation triple fault during resume
commit ec527c318036a65a083ef68d8ba95789d2212246 upstream.

As explained in

	0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once")

we always, no matter what, have to bring up x86 HT siblings during boot at
least once in order to avoid first MCE bringing the system to its knees.

That means that whenever 'nosmt' is supplied on the kernel command-line,
all the HT siblings are as a result sitting in mwait or cpudile after
going through the online-offline cycle at least once.

This causes a serious issue though when a kernel, which saw 'nosmt' on its
commandline, is going to perform resume from hibernation: if the resume
from the hibernated image is successful, cr3 is flipped in order to point
to the address space of the kernel that is being resumed, which in turn
means that all the HT siblings are all of a sudden mwaiting on address
which is no longer valid.

That results in triple fault shortly after cr3 is switched, and machine
reboots.

Fix this by always waking up all the SMT siblings before initiating the
'restore from hibernation' process; this guarantees that all the HT
siblings will be properly carried over to the resumed kernel waiting in
resume_play_dead(), and acted upon accordingly afterwards, based on the
target kernel configuration.

Symmetricaly, the resumed kernel has to push the SMT siblings to mwait
again in case it has SMT disabled; this means it has to online all
the siblings when resuming (so that they come out of hlt) and offline
them again to let them reach mwait.

Cc: 4.19+ <stable@vger.kernel.org> # v4.19+
Debugged-by: Thomas Gleixner <tglx@linutronix.de>
Fixes: 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:22:48 +02:00
Linus Torvalds
0b1a236081 rcu: locking and unlocking need to always be at least barriers
commit 66be4e66a7f422128748e3c3ef6ee72b20a6197b upstream.

Herbert Xu pointed out that commit bb73c52bad ("rcu: Don't disable
preemption for Tiny and Tree RCU readers") was incorrect in making the
preempt_disable/enable() be conditional on CONFIG_PREEMPT_COUNT.

If CONFIG_PREEMPT_COUNT isn't enabled, the preemption enable/disable is
a no-op, but still is a compiler barrier.

And RCU locking still _needs_ that compiler barrier.

It is simply fundamentally not true that RCU locking would be a complete
no-op: we still need to guarantee (for example) that things that can
trap and cause preemption cannot migrate into the RCU locked region.

The way we do that is by making it a barrier.

See for example commit 386afc9114 ("spinlocks and preemption points
need to be at least compiler barriers") from back in 2013 that had
similar issues with spinlocks that become no-ops on UP: they must still
constrain the compiler from moving other operations into the critical
region.

Now, it is true that a lot of RCU operations already use READ_ONCE() and
WRITE_ONCE() (which in practice likely would never be re-ordered wrt
anything remotely interesting), but it is also true that that is not
globally the case, and that it's not even necessarily always possible
(ie bitfields etc).

Reported-by: Herbert Xu <herbert@gondor.apana.org.au>
Fixes: bb73c52bad ("rcu: Don't disable preemption for Tiny and Tree RCU readers")
Cc: stable@kernel.org
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:22:47 +02:00
Ard Biesheuvel
8fca3c3646 efi/libstub: Unify command line param parsing
commit 60f38de7a8d4e816100ceafd1b382df52527bd50 upstream.

Merge the parsing of the command line carried out in arm-stub.c with
the handling in efi_parse_options(). Note that this also fixes the
missing handling of CONFIG_CMDLINE_FORCE=y, in which case the builtin
command line should supersede the one passed by the firmware.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bhe@redhat.com
Cc: bhsharma@redhat.com
Cc: bp@alien8.de
Cc: eugene@hp.com
Cc: evgeny.kalugin@intel.com
Cc: jhugo@codeaurora.org
Cc: leif.lindholm@linaro.org
Cc: linux-efi@vger.kernel.org
Cc: mark.rutland@arm.com
Cc: roy.franz@cavium.com
Cc: rruigrok@codeaurora.org
Link: http://lkml.kernel.org/r/20170404160910.28115-1-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[ardb: fix up merge conflicts with 4.9.180]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:22:45 +02:00
Linus Torvalds
96019c6914 mm: make page ref count overflow check tighter and more explicit
commit f958d7b528b1b40c44cfda5eabe2d82760d868c3 upstream.

We have a VM_BUG_ON() to check that the page reference count doesn't
underflow (or get close to overflow) by checking the sign of the count.

That's all fine, but we actually want to allow people to use a "get page
ref unless it's already very high" helper function, and we want that one
to use the sign of the page ref (without triggering this VM_BUG_ON).

Change the VM_BUG_ON to only check for small underflows (or _very_ close
to overflowing), and ignore overflows which have strayed into negative
territory.

Acked-by: Matthew Wilcox <willy@infradead.org>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:22:45 +02:00
Matthew Wilcox
9557090582 fs: prevent page refcount overflow in pipe_buf_get
commit 15fab63e1e57be9fdb5eec1bbc5916e9825e9acb upstream.

Change pipe_buf_get() to return a bool indicating whether it succeeded
in raising the refcount of the page (if the thing in the pipe is a page).
This removes another mechanism for overflowing the page refcount.  All
callers converted to handle a failure.

Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 4.9: adjust context]
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:22:45 +02:00
Jiri Slaby
0b45276928 memcg: make it work on sparse non-0-node systems
commit 3e8589963773a5c23e2f1fe4bcad0e9a90b7f471 upstream.

We have a single node system with node 0 disabled:
  Scanning NUMA topology in Northbridge 24
  Number of physical nodes 2
  Skipping disabled node 0
  Node 1 MemBase 0000000000000000 Limit 00000000fbff0000
  NODE_DATA(1) allocated [mem 0xfbfda000-0xfbfeffff]

This causes crashes in memcg when system boots:
  BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
  #PF error: [normal kernel read fault]
...
  RIP: 0010:list_lru_add+0x94/0x170
...
  Call Trace:
   d_lru_add+0x44/0x50
   dput.part.34+0xfc/0x110
   __fput+0x108/0x230
   task_work_run+0x9f/0xc0
   exit_to_usermode_loop+0xf5/0x100

It is reproducible as far as 4.12.  I did not try older kernels.  You have
to have a new enough systemd, e.g.  241 (the reason is unknown -- was not
investigated).  Cannot be reproduced with systemd 234.

The system crashes because the size of lru array is never updated in
memcg_update_all_list_lrus and the reads are past the zero-sized array,
causing dereferences of random memory.

The root cause are list_lru_memcg_aware checks in the list_lru code.  The
test in list_lru_memcg_aware is broken: it assumes node 0 is always
present, but it is not true on some systems as can be seen above.

So fix this by avoiding checks on node 0.  Remember the memcg-awareness by
a bool flag in struct list_lru.

Link: http://lkml.kernel.org/r/20190522091940.3615-1-jslaby@suse.cz
Fixes: 60d3fd32a7 ("list_lru: introduce per-memcg lists")
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:22:42 +02:00
Rasmus Villemoes
e186b19bc3 include/linux/bitops.h: sanitize rotate primitives
commit ef4d6f6b275c498f8e5626c99dbeefdc5027f843 upstream.

The ror32 implementation (word >> shift) | (word << (32 - shift) has
undefined behaviour if shift is outside the [1, 31] range.  Similarly
for the 64 bit variants.  Most callers pass a compile-time constant
(naturally in that range), but there's an UBSAN report that these may
actually be called with a shift count of 0.

Instead of special-casing that, we can make them DTRT for all values of
shift while also avoiding UB.  For some reason, this was already partly
done for rol32 (which was well-defined for [0, 31]).  gcc 8 recognizes
these patterns as rotates, so for example

  __u32 rol32(__u32 word, unsigned int shift)
  {
	return (word << (shift & 31)) | (word >> ((-shift) & 31));
  }

compiles to

0000000000000020 <rol32>:
  20:   89 f8                   mov    %edi,%eax
  22:   89 f1                   mov    %esi,%ecx
  24:   d3 c0                   rol    %cl,%eax
  26:   c3                      retq

Older compilers unfortunately do not do as well, but this only affects
the small minority of users that don't pass constants.

Due to integer promotions, ro[lr]8 were already well-defined for shifts
in [0, 8], and ro[lr]16 were mostly well-defined for shifts in [0, 16]
(only mostly - u16 gets promoted to _signed_ int, so if bit 15 is set,
word << 16 is undefined).  For consistency, update those as well.

Link: http://lkml.kernel.org/r/20190410211906.2190-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reported-by: Ido Schimmel <idosch@mellanox.com>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Cc: Vadim Pasternak <vadimp@mellanox.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-11 12:22:36 +02:00
Greg Kroah-Hartman
3f006d43bd Merge 4.9.180 into android-4.9-q
Changes in 4.9.180
	ext4: do not delete unlinked inode from orphan list on failed truncate
	KVM: x86: fix return value for reserved EFER
	bio: fix improper use of smp_mb__before_atomic()
	Revert "scsi: sd: Keep disk read-only when re-reading partition"
	crypto: vmx - CTR: always increment IV as quadword
	kvm: svm/avic: fix off-by-one in checking host APIC ID
	libnvdimm/namespace: Fix label tracking error
	arm64: Save and restore OSDLR_EL1 across suspend/resume
	gfs2: Fix sign extension bug in gfs2_update_stats
	Btrfs: do not abort transaction at btrfs_update_root() after failure to COW path
	Btrfs: fix race between ranged fsync and writeback of adjacent ranges
	btrfs: sysfs: don't leak memory when failing add fsid
	fbdev: fix divide error in fb_var_to_videomode
	hugetlb: use same fault hash key for shared and private mappings
	fbdev: fix WARNING in __alloc_pages_nodemask bug
	media: cpia2: Fix use-after-free in cpia2_exit
	media: vivid: use vfree() instead of kfree() for dev->bitmap_cap
	ssb: Fix possible NULL pointer dereference in ssb_host_pcmcia_exit
	at76c50x-usb: Don't register led_trigger if usb_register_driver failed
	perf tools: No need to include bitops.h in util.h
	tools include: Adopt linux/bits.h
	Revert "btrfs: Honour FITRIM range constraints during free space trim"
	gfs2: Fix lru_count going negative
	cxgb4: Fix error path in cxgb4_init_module
	mmc: core: Verify SD bus width
	dmaengine: tegra210-dma: free dma controller in remove()
	net: ena: gcc 8: fix compilation warning
	ASoC: hdmi-codec: unlock the device on startup errors
	powerpc/boot: Fix missing check of lseek() return value
	ASoC: imx: fix fiq dependencies
	spi: pxa2xx: fix SCR (divisor) calculation
	brcm80211: potential NULL dereference in brcmf_cfg80211_vndr_cmds_dcmd_handler()
	ARM: vdso: Remove dependency with the arch_timer driver internals
	arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable
	sched/cpufreq: Fix kobject memleak
	scsi: qla2xxx: Fix a qla24xx_enable_msix() error path
	iwlwifi: pcie: don't crash on invalid RX interrupt
	rtc: 88pm860x: prevent use-after-free on device remove
	w1: fix the resume command API
	dmaengine: pl330: _stop: clear interrupt status
	mac80211/cfg80211: update bss channel on channel switch
	ASoC: fsl_sai: Update is_slave_mode with correct value
	mwifiex: prevent an array overflow
	net: cw1200: fix a NULL pointer dereference
	crypto: sun4i-ss - Fix invalid calculation of hash end
	bcache: return error immediately in bch_journal_replay()
	bcache: fix failure in journal relplay
	bcache: add failure check to run_cache_set() for journal replay
	bcache: avoid clang -Wunintialized warning
	x86/build: Move _etext to actual end of .text
	smpboot: Place the __percpu annotation correctly
	x86/mm: Remove in_nmi() warning from 64-bit implementation of vmalloc_fault()
	mm/uaccess: Use 'unsigned long' to placate UBSAN warnings on older GCC versions
	HID: logitech-hidpp: use RAP instead of FAP to get the protocol version
	pinctrl: pistachio: fix leaked of_node references
	dmaengine: at_xdmac: remove BUG_ON macro in tasklet
	media: coda: clear error return value before picture run
	media: ov6650: Move v4l2_clk_get() to ov6650_video_probe() helper
	media: au0828: stop video streaming only when last user stops
	media: ov2659: make S_FMT succeed even if requested format doesn't match
	audit: fix a memory leak bug
	media: au0828: Fix NULL pointer dereference in au0828_analog_stream_enable()
	media: pvrusb2: Prevent a buffer overflow
	powerpc/numa: improve control of topology updates
	sched/core: Check quota and period overflow at usec to nsec conversion
	sched/core: Handle overflow in cpu_shares_write_u64
	USB: core: Don't unbind interfaces following device reset failure
	x86/irq/64: Limit IST stack overflow check to #DB stack
	i40e: don't allow changes to HW VLAN stripping on active port VLANs
	arm64: vdso: Fix clock_getres() for CLOCK_REALTIME
	RDMA/cxgb4: Fix null pointer dereference on alloc_skb failure
	hwmon: (vt1211) Use request_muxed_region for Super-IO accesses
	hwmon: (smsc47m1) Use request_muxed_region for Super-IO accesses
	hwmon: (smsc47b397) Use request_muxed_region for Super-IO accesses
	hwmon: (pc87427) Use request_muxed_region for Super-IO accesses
	hwmon: (f71805f) Use request_muxed_region for Super-IO accesses
	scsi: libsas: Do discovery on empty PHY to update PHY info
	mmc: core: make pwrseq_emmc (partially) support sleepy GPIO controllers
	mmc_spi: add a status check for spi_sync_locked
	mmc: sdhci-of-esdhc: add erratum eSDHC5 support
	mmc: sdhci-of-esdhc: add erratum eSDHC-A001 and A-008358 support
	PM / core: Propagate dev->power.wakeup_path when no callbacks
	extcon: arizona: Disable mic detect if running when driver is removed
	s390: cio: fix cio_irb declaration
	cpufreq: ppc_cbe: fix possible object reference leak
	cpufreq/pasemi: fix possible object reference leak
	cpufreq: pmac32: fix possible object reference leak
	x86/build: Keep local relocations with ld.lld
	iio: ad_sigma_delta: Properly handle SPI bus locking vs CS assertion
	iio: hmc5843: fix potential NULL pointer dereferences
	iio: common: ssp_sensors: Initialize calculated_time in ssp_common_process_data
	rtlwifi: fix a potential NULL pointer dereference
	mwifiex: Fix mem leak in mwifiex_tm_cmd
	brcmfmac: fix missing checks for kmemdup
	b43: shut up clang -Wuninitialized variable warning
	brcmfmac: convert dev_init_lock mutex to completion
	brcmfmac: fix race during disconnect when USB completion is in progress
	brcmfmac: fix Oops when bringing up interface during USB disconnect
	scsi: ufs: Fix regulator load and icc-level configuration
	scsi: ufs: Avoid configuring regulator with undefined voltage range
	arm64: cpu_ops: fix a leaked reference by adding missing of_node_put
	x86/uaccess, signal: Fix AC=1 bloat
	x86/ia32: Fix ia32_restore_sigcontext() AC leak
	chardev: add additional check for minor range overlap
	HID: core: move Usage Page concatenation to Main item
	ASoC: eukrea-tlv320: fix a leaked reference by adding missing of_node_put
	ASoC: fsl_utils: fix a leaked reference by adding missing of_node_put
	cxgb3/l2t: Fix undefined behaviour
	spi: tegra114: reset controller on probe
	media: wl128x: prevent two potential buffer overflows
	virtio_console: initialize vtermno value for ports
	tty: ipwireless: fix missing checks for ioremap
	x86/mce: Fix machine_check_poll() tests for error types
	rcutorture: Fix cleanup path for invalid torture_type strings
	rcuperf: Fix cleanup path for invalid perf_type strings
	usb: core: Add PM runtime calls to usb_hcd_platform_shutdown
	scsi: qla4xxx: avoid freeing unallocated dma memory
	dmaengine: tegra210-adma: use devm_clk_*() helpers
	media: m88ds3103: serialize reset messages in m88ds3103_set_frontend
	media: go7007: avoid clang frame overflow warning with KASAN
	scsi: lpfc: Fix FDMI manufacturer attribute value
	media: saa7146: avoid high stack usage with clang
	scsi: lpfc: Fix SLI3 commands being issued on SLI4 devices
	spi : spi-topcliff-pch: Fix to handle empty DMA buffers
	spi: rspi: Fix sequencer reset during initialization
	spi: Fix zero length xfer bug
	ASoC: davinci-mcasp: Fix clang warning without CONFIG_PM
	drm: Wake up next in drm_read() chain if we are forced to putback the event
	Linux 4.9.180

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-05-31 08:40:27 -07:00
Nicolas Saenz Julienne
1410277e19 HID: core: move Usage Page concatenation to Main item
[ Upstream commit 58e75155009cc800005629955d3482f36a1e0eec ]

As seen on some USB wireless keyboards manufactured by Primax, the HID
parser was using some assumptions that are not always true. In this case
it's s the fact that, inside the scope of a main item, an Usage Page
will always precede an Usage.

The spec is not pretty clear as 6.2.2.7 states "Any usage that follows
is interpreted as a Usage ID and concatenated with the Usage Page".
While 6.2.2.8 states "When the parser encounters a main item it
concatenates the last declared Usage Page with a Usage to form a
complete usage value." Being somewhat contradictory it was decided to
match Window's implementation, which follows 6.2.2.8.

In summary, the patch moves the Usage Page concatenation from the local
item parsing function to the main item parsing function.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Terry Junge <terry.junge@poly.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31 06:48:29 -07:00
Lars-Peter Clausen
0ce6473c39 iio: ad_sigma_delta: Properly handle SPI bus locking vs CS assertion
[ Upstream commit df1d80aee963480c5c2938c64ec0ac3e4a0df2e0 ]

For devices from the SigmaDelta family we need to keep CS low when doing a
conversion, since the device will use the MISO line as a interrupt to
indicate that the conversion is complete.

This is why the driver locks the SPI bus and when the SPI bus is locked
keeps as long as a conversion is going on. The current implementation gets
one small detail wrong though. CS is only de-asserted after the SPI bus is
unlocked. This means it is possible for a different SPI device on the same
bus to send a message which would be wrongfully be addressed to the
SigmaDelta device as well. Make sure that the last SPI transfer that is
done while holding the SPI bus lock de-asserts the CS signal.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <Alexandru.Ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31 06:48:27 -07:00
Sebastian Andrzej Siewior
a5f3559f30 smpboot: Place the __percpu annotation correctly
[ Upstream commit d4645d30b50d1691c26ff0f8fa4e718b08f8d3bb ]

The test robot reported a wrong assignment of a per-CPU variable which
it detected by using sparse and sent a report. The assignment itself is
correct. The annotation for sparse was wrong and hence the report.
The first pointer is a "normal" pointer and points to the per-CPU memory
area. That means that the __percpu annotation has to be moved.

Move the __percpu annotation to pointer which points to the per-CPU
area. This change affects only the sparse tool (and is ignored by the
compiler).

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: f97f8f06a4 ("smpboot: Provide infrastructure for percpu hotplug threads")
Link: http://lkml.kernel.org/r/20190424085253.12178-1-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31 06:48:17 -07:00
Mike Kravetz
f0539c7018 hugetlb: use same fault hash key for shared and private mappings
commit 1b426bac66e6cc83c9f2d92b96e4e72acf43419a upstream.

hugetlb uses a fault mutex hash table to prevent page faults of the
same pages concurrently.  The key for shared and private mappings is
different.  Shared keys off address_space and file index.  Private keys
off mm and virtual address.  Consider a private mappings of a populated
hugetlbfs file.  A fault will map the page from the file and if needed
do a COW to map a writable page.

Hugetlbfs hole punch uses the fault mutex to prevent mappings of file
pages.  It uses the address_space file index key.  However, private
mappings will use a different key and could race with this code to map
the file page.  This causes problems (BUG) for the page cache remove
code as it expects the page to be unmapped.  A sample stack is:

page dumped because: VM_BUG_ON_PAGE(page_mapped(page))
kernel BUG at mm/filemap.c:169!
...
RIP: 0010:unaccount_page_cache_page+0x1b8/0x200
...
Call Trace:
__delete_from_page_cache+0x39/0x220
delete_from_page_cache+0x45/0x70
remove_inode_hugepages+0x13c/0x380
? __add_to_page_cache_locked+0x162/0x380
hugetlbfs_fallocate+0x403/0x540
? _cond_resched+0x15/0x30
? __inode_security_revalidate+0x5d/0x70
? selinux_file_permission+0x100/0x130
vfs_fallocate+0x13f/0x270
ksys_fallocate+0x3c/0x80
__x64_sys_fallocate+0x1a/0x20
do_syscall_64+0x5b/0x180
entry_SYSCALL_64_after_hwframe+0x44/0xa9

There seems to be another potential COW issue/race with this approach
of different private and shared keys as noted in commit 8382d914eb
("mm, hugetlb: improve page-fault scalability").

Since every hugetlb mapping (even anon and private) is actually a file
mapping, just use the address_space index key for all mappings.  This
results in potentially more hash collisions.  However, this should not
be the common case.

Link: http://lkml.kernel.org/r/20190328234704.27083-3-mike.kravetz@oracle.com
Link: http://lkml.kernel.org/r/20190412165235.t4sscoujczfhuiyt@linux-r8p5
Fixes: b5cec28d36 ("hugetlbfs: truncate_hugepages() takes a range of pages")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-31 06:48:12 -07:00