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authorKan Liang <kan.liang@intel.com>2016-11-15 13:40:10 -0500
committerIngo Molnar <mingo@kernel.org>2016-11-16 09:46:35 +0100
commitc499336cea8bbe15554c6fcea2138658c5395bfe (patch)
tree7ae5419d8309f8e61633778f513b131b15eba3f4 /arch/x86/events
parent864c2357ca898c6171fe5284f5ecc795c8ce27a8 (diff)
perf/x86/uncore: Fix crash by removing bogus event_list[] handling for SNB client uncore IMC
Vince Weaver reported the following bug when KASAN is enabled: [ 205.748005] BUG: KASAN: slab-out-of-bounds in snb_uncore_imc_event_del+0x6c/0xa0 at addr ffff8800caa43768 [ 205.758324] Read of size 8 by task perf_fuzzer/6618 It's caused by accessing box->event_list. For client IMC, there are no generic counters. It defines its own fixed free running counters. So event_list and n_events are unused. They can be removed safely, which fixes the bug. ( There's still the separate question of how uninitialized state snuck into this data structure - but that's a separate fix. ) Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Kan Liang <kan.liang@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: acme@kernel.org Cc: davej@codemonkey.org.uk Cc: dvyukov@google.com Cc: eranian@gmail.com Link: http://lkml.kernel.org/r/1479235210-29090-1-git-send-email-kan.liang@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/events')
-rw-r--r--arch/x86/events/intel/uncore_snb.c12
1 files changed, 0 insertions, 12 deletions
diff --git a/arch/x86/events/intel/uncore_snb.c b/arch/x86/events/intel/uncore_snb.c
index 81195cca7eae..a3dcc12bef4a 100644
--- a/arch/x86/events/intel/uncore_snb.c
+++ b/arch/x86/events/intel/uncore_snb.c
@@ -490,24 +490,12 @@ static int snb_uncore_imc_event_add(struct perf_event *event, int flags)
snb_uncore_imc_event_start(event, 0);
- box->n_events++;
-
return 0;
}
static void snb_uncore_imc_event_del(struct perf_event *event, int flags)
{
- struct intel_uncore_box *box = uncore_event_to_box(event);
- int i;
-
snb_uncore_imc_event_stop(event, PERF_EF_UPDATE);
-
- for (i = 0; i < box->n_events; i++) {
- if (event == box->event_list[i]) {
- --box->n_events;
- break;
- }
- }
}
int snb_pci2phy_map_init(int devid)