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authorThomas Gleixner <tglx@linutronix.de>2016-02-09 20:11:34 +0000
committerIngo Molnar <mingo@kernel.org>2016-02-17 10:37:30 +0100
commit059fcd8cd16622da6513804a7a3e826d152c6c96 (patch)
parent27ca9236c96f4a21b72a2b4f08260efeab951bd0 (diff)
perf/core: Plug potential memory leak in CPU_UP_PREPARE
If CPU_UP_PREPARE is called it is not guaranteed, that a previously allocated and assigned hash has been freed already, but perf_event_init_cpu() unconditionally allocates and assignes a new hash if the swhash is referenced. By overwriting the pointer the existing hash is not longer accessible. Verify that there is no hash assigned on this cpu before allocating and assigning a new one. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/20160209201007.843269966@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 4aa64a85a7b7..0d58522103cd 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9206,7 +9206,7 @@ static void perf_event_init_cpu(int cpu)
struct swevent_htable *swhash = &per_cpu(swevent_htable, cpu);
- if (swhash->hlist_refcount > 0) {
+ if (swhash->hlist_refcount > 0 && !swevent_hlist_deref(swhash)) {
struct swevent_hlist *hlist;
hlist = kzalloc_node(sizeof(*hlist), GFP_KERNEL, cpu_to_node(cpu));