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| author | Kan Liang <kan.liang@intel.com> | 2016-11-15 13:40:10 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-11-16 09:46:35 +0100 |
| commit | c499336cea8bbe15554c6fcea2138658c5395bfe (patch) | |
| tree | 7ae5419d8309f8e61633778f513b131b15eba3f4 /arch/x86 | |
| parent | 864c2357ca898c6171fe5284f5ecc795c8ce27a8 (diff) | |
| download | linux-c499336cea8bbe15554c6fcea2138658c5395bfe.tar.gz linux-c499336cea8bbe15554c6fcea2138658c5395bfe.tar.xz | |
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')
| -rw-r--r-- | arch/x86/events/intel/uncore_snb.c | 12 |
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) |