5.4-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Gleixner tglx@linutronix.de
commit 07091aade394f690e7b655578140ef84d0e8d7b0 upstream.
When perf_mmap() fails to allocate a buffer, it still invokes the event_mapped() callback of the related event. On X86 this might increase the perf_rdpmc_allowed reference counter. But nothing undoes this as perf_mmap_close() is never called in this case, which causes another reference count leak.
Return early on failure to prevent that.
Fixes: 1e0fb9ec679c ("perf/core: Add pmu callbacks to track event mapping and unmapping") Signed-off-by: Thomas Gleixner tglx@linutronix.de Reviewed-by: Lorenzo Stoakes lorenzo.stoakes@oracle.comCc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/events/core.c | 3 +++ 1 file changed, 3 insertions(+)
--- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6003,6 +6003,9 @@ unlock: aux_unlock: mutex_unlock(&event->mmap_mutex);
+ if (ret) + return ret; + /* * Since pinned accounting is per vm we cannot allow fork() to copy our * vma.