nixiaoming 68d3bc40f5 tty fix oops when rmmod 8250 ...

[ Upstream commit c79dde629d2027ca80329c62854a7635e623d527 ]

After rmmod 8250.ko
tty_kref_put starts kwork (release_one_tty) to release proc interface
oops when accessing driver->driver_name in proc_tty_unregister_driver

Use jprobe, found driver->driver_name point to 8250.ko
static static struct uart_driver serial8250_reg
.driver_name= serial,

Use name in proc_dir_entry instead of driver->driver_name to fix oops

test on linux 4.1.12:

BUG: unable to handle kernel paging request at ffffffffa01979de
IP: [<ffffffff81310f40>] strchr+0x0/0x30
PGD 1a0d067 PUD 1a0e063 PMD 851c1f067 PTE 0
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: ... ...  [last unloaded: 8250]
CPU: 7 PID: 116 Comm: kworker/7:1 Tainted: G           O    4.1.12 #1
Hardware name: Insyde RiverForest/Type2 - Board Product Name1, BIOS NE5KV904 12/21/2015
Workqueue: events release_one_tty
task: ffff88085b684960 ti: ffff880852884000 task.ti: ffff880852884000
RIP: 0010:[<ffffffff81310f40>]  [<ffffffff81310f40>] strchr+0x0/0x30
RSP: 0018:ffff880852887c90  EFLAGS: 00010282
RAX: ffffffff81a5eca0 RBX: ffffffffa01979de RCX: 0000000000000004
RDX: ffff880852887d10 RSI: 000000000000002f RDI: ffffffffa01979de
RBP: ffff880852887cd8 R08: 0000000000000000 R09: ffff88085f5d94d0
R10: 0000000000000195 R11: 0000000000000000 R12: ffffffffa01979de
R13: ffff880852887d00 R14: ffffffffa01979de R15: ffff88085f02e840
FS:  0000000000000000(0000) GS:ffff88085f5c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffa01979de CR3: 0000000001a0c000 CR4: 00000000001406e0
Stack:
 ffffffff812349b1 ffff880852887cb8 ffff880852887d10 ffff88085f5cd6c2
 ffff880852800a80 ffffffffa01979de ffff880852800a84 0000000000000010
 ffff88085bb28bd8 ffff880852887d38 ffffffff812354f0 ffff880852887d08
Call Trace:
 [<ffffffff812349b1>] ? __xlate_proc_name+0x71/0xd0
 [<ffffffff812354f0>] remove_proc_entry+0x40/0x180
 [<ffffffff815f6811>] ? _raw_spin_lock_irqsave+0x41/0x60
 [<ffffffff813be520>] ? destruct_tty_driver+0x60/0xe0
 [<ffffffff81237c68>] proc_tty_unregister_driver+0x28/0x40
 [<ffffffff813be548>] destruct_tty_driver+0x88/0xe0
 [<ffffffff813be5bd>] tty_driver_kref_put+0x1d/0x20
 [<ffffffff813becca>] release_one_tty+0x5a/0xd0
 [<ffffffff81074159>] process_one_work+0x139/0x420
 [<ffffffff810745a1>] worker_thread+0x121/0x450
 [<ffffffff81074480>] ? process_scheduled_works+0x40/0x40
 [<ffffffff8107a16c>] kthread+0xec/0x110
 [<ffffffff81080000>] ? tg_rt_schedulable+0x210/0x220
 [<ffffffff8107a080>] ? kthread_freezable_should_stop+0x80/0x80
 [<ffffffff815f7292>] ret_from_fork+0x42/0x70
 [<ffffffff8107a080>] ? kthread_freezable_should_stop+0x80/0x80

Signed-off-by: nixiaoming <nixiaoming@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2017-12-20 10:05:00 +01:00

..

array.c

ptrace: use fsuid, fsgid, effective creds for fs access checks

2016-02-25 12:01:16 -08:00

base.c

proc: add a schedule point in proc_pid_readdir()

2017-06-17 06:39:38 +02:00

cmdline.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

consoles.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

cpuinfo.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

devices.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

fd.c

proc: actually make proc_fd_permission() thread-friendly

2015-11-06 17:50:42 -08:00

fd.h

proc: Move proc_fd() to fs/proc/fd.h

2013-05-01 17:29:39 -04:00

generic.c

proc: Fix unbalanced hard link numbers

2017-05-25 14:30:10 +02:00

inode.c

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2015-07-03 15:20:57 -07:00

internal.h

proc: Allow creating permanently empty directories that serve as mount points

2015-07-01 10:36:41 -05:00

interrupts.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

Kconfig

fs, proc: add help for CONFIG_PROC_CHILDREN

2015-07-17 16:39:52 -07:00

kcore.c

x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86

2015-07-18 03:42:51 +02:00

kmsg.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

loadavg.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

Makefile

proc: Implement /proc/thread-self to point at the directory of the current thread

2014-08-04 10:07:11 -07:00

meminfo.c

mm: get rid of 'vmalloc_info' from /proc/meminfo

2015-11-01 17:09:15 -08:00

namespaces.c

ptrace: use fsuid, fsgid, effective creds for fs access checks

2016-02-25 12:01:16 -08:00

nommu.c

vfs: add seq_file_path() helper

2015-06-23 18:01:07 -04:00

page.c

proc: add cond_resched to /proc/kpage* read/write loop

2015-09-10 13:29:01 -07:00

proc_net.c

VFS: normal filesystems (and lustre): d_inode() annotations

2015-04-15 15:06:57 -04:00

proc_sysctl.c

sysctl: Drop reference added by grab_header in proc_sys_readdir

2017-01-19 20:17:21 +01:00

proc_tty.c

tty fix oops when rmmod 8250

2017-12-20 10:05:00 +01:00

root.c

proc: prevent stacking filesystems on top

2016-06-24 10:18:20 -07:00

self.c

don't pass nameidata to ->follow_link()

2015-05-10 22:20:15 -04:00

softirqs.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

stat.c

genirq: Prevent proc race against freeing of irq descriptors

2014-12-13 13:33:07 +01:00

task_mmu.c

mm: larger stack guard gap, between vmas

2017-06-26 07:13:11 +02:00

task_nommu.c

proc: revert /proc/<pid>/maps [stack:TID] annotation

2016-09-15 08:27:46 +02:00

thread_self.c

don't pass nameidata to ->follow_link()

2015-05-10 22:20:15 -04:00

uptime.c

cputime: Default implementation of nsecs -> cputime conversion

2014-03-13 15:56:43 +01:00

version.c

fs/proc: don't use module_init for non-modular core code

2014-01-23 16:37:02 -08:00

vmcore.c

vmcore: fix PT_NOTE n_namesz, n_descsz overflow issue

2015-02-17 14:34:52 -08:00