Messages in this thread | | | Date | Thu, 10 Sep 2015 00:48:31 -0400 | From | Sasha Levin <> | Subject | Re: [PATCH 01/10] perf,x86: Fix event/group validation |
| |
Ping?
On 08/21/2015 04:31 PM, Sasha Levin wrote: > On 05/21/2015 07:17 AM, Peter Zijlstra wrote: >> --- a/arch/x86/kernel/cpu/perf_event_intel.c >> +++ b/arch/x86/kernel/cpu/perf_event_intel.c >> @@ -2106,7 +2106,7 @@ static struct event_constraint * >> intel_get_event_constraints(struct cpu_hw_events *cpuc, int idx, >> struct perf_event *event) >> { >> - struct event_constraint *c1 = event->hw.constraint; >> + struct event_constraint *c1 = cpuc->event_constraint[idx]; >> struct event_constraint *c2; > > Hey Peter, > > I was chasing a memory corruption in this area and I think I found > a possible culprit: > > After this patch, In the code above, we'd access "cpuc->event_constraint[idx]" > and read/change memory. > > The problem is that a valid value for idx is also -1, which isn't checked > here, so we end up accessing and possibly corrupting memory that isn't ours. > > > Thanks, > Sasha >
| |