diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index 7fd7e8419c7f..559416c2034b 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -678,7 +678,8 @@ allowed to execute. perf_event_paranoid: Controls use of the performance events system by unprivileged -users (without CAP_SYS_ADMIN). The default value is 2. +users (without CAP_SYS_ADMIN). The default value is 3 if +CONFIG_SECURITY_PERF_EVENTS_RESTRICT is set, or 2 otherwise. -1: Allow use of (almost) all events by all users Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK @@ -686,6 +687,7 @@ users (without CAP_SYS_ADMIN). The default value is 2. Disallow raw tracepoint access by users without CAP_SYS_ADMIN >=1: Disallow CPU event access by users without CAP_SYS_ADMIN >=2: Disallow kernel profiling by users without CAP_SYS_ADMIN +>=3: Disallow all event access by users without CAP_SYS_ADMIN ============================================================== diff --git a/arch/arm64/configs/cuttlefish_defconfig b/arch/arm64/configs/cuttlefish_defconfig index a198f84e007a..d06e88fa0aa1 100644 --- a/arch/arm64/configs/cuttlefish_defconfig +++ b/arch/arm64/configs/cuttlefish_defconfig @@ -466,6 +466,7 @@ CONFIG_RCU_CPU_STALL_TIMEOUT=60 CONFIG_ENABLE_DEFAULT_TRACERS=y CONFIG_TEST_MEMINIT=y CONFIG_TEST_STACKINIT=y +CONFIG_SECURITY_PERF_EVENTS_RESTRICT=y CONFIG_SECURITY=y CONFIG_SECURITY_NETWORK=y CONFIG_LSM_MMAP_MIN_ADDR=65536 diff --git a/arch/x86/configs/x86_64_cuttlefish_defconfig b/arch/x86/configs/x86_64_cuttlefish_defconfig index c32c29d94182..e0c6292d05f9 100644 --- a/arch/x86/configs/x86_64_cuttlefish_defconfig +++ b/arch/x86/configs/x86_64_cuttlefish_defconfig @@ -499,6 +499,7 @@ CONFIG_TEST_STACKINIT=y CONFIG_IO_DELAY_NONE=y CONFIG_OPTIMIZE_INLINING=y CONFIG_UNWINDER_FRAME_POINTER=y +CONFIG_SECURITY_PERF_EVENTS_RESTRICT=y CONFIG_SECURITY=y CONFIG_SECURITY_NETWORK=y CONFIG_SECURITY_PATH=y diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index eae4331bb2d0..621342fbb3b4 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1207,6 +1207,11 @@ int perf_event_max_stack_handler(struct ctl_table *table, int write, #define PERF_SECURITY_KERNEL 2 #define PERF_SECURITY_TRACEPOINT 3 +static inline bool perf_paranoid_any(void) +{ + return sysctl_perf_event_paranoid > 2; +} + static inline int perf_is_paranoid(void) { return sysctl_perf_event_paranoid > -1; diff --git a/kernel/events/core.c b/kernel/events/core.c index 27be52961a47..cb84d328303c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -430,8 +430,13 @@ static cpumask_var_t perf_online_mask; * 0 - disallow raw tracepoint access for unpriv * 1 - disallow cpu events for unpriv * 2 - disallow kernel profiling for unpriv + * 3 - disallow all unpriv perf event use */ +#ifdef CONFIG_SECURITY_PERF_EVENTS_RESTRICT +int sysctl_perf_event_paranoid __read_mostly = 3; +#else int sysctl_perf_event_paranoid __read_mostly = 2; +#endif /* Minimum for 512 kiB + 1 user control page */ int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ @@ -10412,6 +10417,9 @@ SYSCALL_DEFINE5(perf_event_open, if (flags & ~PERF_FLAG_ALL) return -EINVAL; + if (perf_paranoid_any() && !capable(CAP_SYS_ADMIN)) + return -EACCES; + /* Do we allow access to perf_event_open(2) ? */ err = security_perf_event_open(&attr, PERF_SECURITY_OPEN); if (err) diff --git a/security/Kconfig b/security/Kconfig index 70022bd5b4bf..daaf13e06d83 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -22,6 +22,15 @@ config SECURITY_DMESG_RESTRICT If you are unsure how to answer this question, answer N. +config SECURITY_PERF_EVENTS_RESTRICT + bool "Restrict unprivileged use of performance events" + depends on PERF_EVENTS + help + If you say Y here, the kernel.perf_event_paranoid sysctl + will be set to 3 by default, and no unprivileged use of the + perf_event_open syscall will be permitted unless it is + changed. + config SECURITY bool "Enable different security models" depends on SYSFS