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perf/core: Exit early on perf_mmap() fail

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commit 07091aade3 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: 1e0fb9ec67 ("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.com>Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Thomas Gleixner 2025-08-02 12:49:48 +02:00 committed by Greg Kroah-Hartman
parent f8346dc122
commit 27d44145bd
1 changed files with 3 additions and 0 deletions
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3
kernel/events/core.c
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@ -6504,6 +6504,9 @@ aux_unlock:
mutex_unlock(aux_mutex);
mutex_unlock(&event->mmap_mutex);
if (ret)
return ret;
/*
* Since pinned accounting is per vm we cannot allow fork() to copy our
* vma.