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authorAlexey Budankov2020-08-05 10:56:56 +0300
committerIngo Molnar2020-08-06 15:03:20 +0200
commit45fd22da97c6125d8d0d35bd1791e7c0c4175279 (patch)
tree5329710d5f59f32fbe1fdc2edfaa083c71a7a13f /kernel/events
parent2324d50d051ec0f14a548e78554fb02513d6dcef (diff)
perf/core: Take over CAP_SYS_PTRACE creds to CAP_PERFMON capability
Open access to per-process monitoring for CAP_PERFMON only privileged processes [1]. Extend ptrace_may_access() check in perf_events subsystem with perfmon_capable() to simplify user experience and make monitoring more secure by reducing attack surface. [1] https://lore.kernel.org/lkml/7776fa40-6c65-2aa6-1322-eb3a01201000@linux.intel.com/ Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/r/6e8392ff-4732-0012-2949-e1587709f0f6@linux.intel.com
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 78e69e10482a..41e0cefb429b 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -11689,7 +11689,7 @@ SYSCALL_DEFINE5(perf_event_open,
goto err_task;
/*
- * Reuse ptrace permission checks for now.
+ * Preserve ptrace permission check for backwards compatibility.
*
* We must hold exec_update_mutex across this and any potential
* perf_install_in_context() call for this new event to
@@ -11697,7 +11697,7 @@ SYSCALL_DEFINE5(perf_event_open,
* perf_event_exit_task() that could imply).
*/
err = -EACCES;
- if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
+ if (!perfmon_capable() && !ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS))
goto err_cred;
}