perf: Fix double-free of the AUX buffer
authorBen Hutchings <ben@decadent.org.uk>
Sun, 26 Jul 2015 23:31:08 +0000 (00:31 +0100)
committerIngo Molnar <mingo@kernel.org>
Wed, 12 Aug 2015 09:37:21 +0000 (11:37 +0200)
commitee9397a6fb9bc4e52677f5e33eed4abee0f515e6
treee651e0dadf1362f500177552d6e99707ff441959
parentfed66e2cdd4f127a43fd11b8d92a99bdd429528c
perf: Fix double-free of the AUX buffer

If rb->aux_refcount is decremented to zero before rb->refcount,
__rb_free_aux() may be called twice resulting in a double free of
rb->aux_pages.  Fix this by adding a check to __rb_free_aux().

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 57ffc5ca679f ("perf: Fix AUX buffer refcounting")
Link: http://lkml.kernel.org/r/1437953468.12842.17.camel@decadent.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
kernel/events/ring_buffer.c