diff options
| -rw-r--r-- | Documentation/sysctl/kernel.txt | 4 | ||||
| -rw-r--r-- | include/linux/perf_event.h | 5 | ||||
| -rw-r--r-- | kernel/events/core.c | 8 | ||||
| -rw-r--r-- | security/Kconfig | 9 |
4 files changed, 25 insertions, 1 deletions
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index f33820824..a8e65f559 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -468,12 +468,14 @@ the existing panic controls already in that directory. perf_event_paranoid: Controls use of the performance events system by unprivileged -users (without CAP_SYS_ADMIN). The default value is 1. +users (without CAP_SYS_ADMIN). The default value is 3 if +CONFIG_SECURITY_PERF_EVENTS_RESTRICT is set, or 1 otherwise. -1: Allow use of (almost) all events by all users >=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK >=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/include/linux/perf_event.h b/include/linux/perf_event.h index 229a757e1..1a9b9118a 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -707,6 +707,11 @@ extern int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write, loff_t *ppos); +static inline bool perf_paranoid_any(void) +{ + return sysctl_perf_event_paranoid > 2; +} + static inline bool perf_paranoid_tracepoint_raw(void) { return sysctl_perf_event_paranoid > -1; diff --git a/kernel/events/core.c b/kernel/events/core.c index 0f5207839..b7045ba1f 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -157,8 +157,13 @@ static struct srcu_struct pmus_srcu; * 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 = 1; +#endif /* Minimum for 512 kiB + 1 user control page */ int sysctl_perf_event_mlock __read_mostly = 512 + (PAGE_SIZE / 1024); /* 'free' kiB per user */ @@ -6725,6 +6730,9 @@ SYSCALL_DEFINE5(perf_event_open, if (flags & ~PERF_FLAG_ALL) return -EINVAL; + if (perf_paranoid_any() && !capable(CAP_SYS_ADMIN)) + return -EACCES; + err = perf_copy_attr(attr_uptr, &attr); if (err) return err; diff --git a/security/Kconfig b/security/Kconfig index e9c6ac724..e37182464 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -18,6 +18,15 @@ 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 |