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Commit 69255ecb authored by Linux Build Service Account's avatar Linux Build Service Account Committed by Gerrit - the friendly Code Review server
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Merge "FROMLIST: security,perf: Allow further restriction of perf_event_open"

parents 2070e176 426646ed

Documentation/sysctl/kernel.txt

+3 −1
Original line number Diff line number Diff line
@@ -617,12 +617,14 @@ 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



==============================================================

include/linux/perf_event.h

+5 −0
Original line number Diff line number Diff line
@@ -753,6 +753,11 @@ 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;

kernel/events/core.c

+6 −0
Original line number Diff line number Diff line
@@ -171,9 +171,12 @@ 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_PERF_EVENTS_USERMODE

int sysctl_perf_event_paranoid __read_mostly = -1;

#elif defined CONFIG_SECURITY_PERF_EVENTS_RESTRICT

int sysctl_perf_event_paranoid __read_mostly = 3;

#else

int sysctl_perf_event_paranoid __read_mostly = 1;

#endif
@@ -7311,6 +7314,9 @@ 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;

security/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -23,6 +23,15 @@ 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