Commit-ID: c499336cea8bbe15554c6fcea2138658c5395bfe
Gitweb: http://git.kernel.org/tip/c499336cea8bbe15554c6fcea2138658c5395bfe
Author: Kan Liang <kan.liang@xxxxxxxxx>
AuthorDate: Tue, 15 Nov 2016 13:40:10 -0500
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 16 Nov 2016 09:46:35 +0100
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@xxxxxxxxx>
Tested-by: Vince Weaver <vincent.weaver@xxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: acme@xxxxxxxxxx
Cc: davej@xxxxxxxxxxxxxxxxx
Cc: dvyukov@xxxxxxxxxx
Cc: eranian@xxxxxxxxx
Link: http://lkml.kernel.org/r/1479235210-29090-1-git-send-email-kan.liang@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/events/intel/uncore_snb.c | 12 ------------
1 file changed, 12 deletions(-)
diff --git a/arch/x86/events/intel/uncore_snb.c b/arch/x86/events/intel/uncore_snb.c
index 81195cc..a3dcc12 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)
--
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