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| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2019-11-01 16:12:48 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2019-11-13 08:16:40 +0100 |
| commit | 00496fe5e09e8c8bb115540e7e3470553cd07a5c (patch) | |
| tree | 728e7803f48b326150c438d85613fc695749189c /kernel | |
| parent | perf/core: Disallow uncore-cgroup events (diff) | |
| download | linux-00496fe5e09e8c8bb115540e7e3470553cd07a5c.tar.xz linux-00496fe5e09e8c8bb115540e7e3470553cd07a5c.zip | |
perf/aux: Fix the aux_output group inheritance fix
Commit
f733c6b508bc ("perf/core: Fix inheritance of aux_output groups")
adds a NULL pointer dereference in case inherit_group() races with
perf_release(), which causes the below crash:
> BUG: kernel NULL pointer dereference, address: 000000000000010b
> #PF: supervisor read access in kernel mode
> #PF: error_code(0x0000) - not-present page
> PGD 3b203b067 P4D 3b203b067 PUD 3b2040067 PMD 0
> Oops: 0000 [#1] SMP KASAN
> CPU: 0 PID: 315 Comm: exclusive-group Tainted: G B 5.4.0-rc3-00181-g72e1839403cb-dirty #878
> RIP: 0010:perf_get_aux_event+0x86/0x270
> Call Trace:
> ? __perf_read_group_add+0x3b0/0x3b0
> ? __kasan_check_write+0x14/0x20
> ? __perf_event_init_context+0x154/0x170
> inherit_task_group.isra.0.part.0+0x14b/0x170
> perf_event_init_task+0x296/0x4b0
Fix this by skipping over events that are getting closed, in the
inheritance path.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: f733c6b508bc ("perf/core: Fix inheritance of aux_output groups")
Link: https://lkml.kernel.org/r/20191101151248.47327-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 022a34b66e60..b752bd3aa03b 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -11899,7 +11899,7 @@ static int inherit_group(struct perf_event *parent_event, if (IS_ERR(child_ctr)) return PTR_ERR(child_ctr); - if (sub->aux_event == parent_event && + if (sub->aux_event == parent_event && child_ctr && !perf_get_aux_event(child_ctr, leader)) return -EINVAL; } |