From ede271b059463731cbd6dffe55ffd70d7dbe8392 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 14 Mar 2019 14:01:14 +0100 Subject: perf/x86/intel: Fix memory corruption Through: validate_event() x86_pmu.get_event_constraints(.idx=-1) tfa_get_event_constraints() dyn_constraint() cpuc->constraint_list[-1] is used, which is an obvious out-of-bound access. In this case, simply skip the TFA constraint code, there is no event constraint with just PMC3, therefore the code will never result in the empty set. Fixes: 400816f60c54 ("perf/x86/intel: Implement support for TSX Force Abort") Reported-by: Tony Jones Reported-by: "DSouza, Nelson" Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Tested-by: Tony Jones Tested-by: "DSouza, Nelson" Cc: eranian@google.com Cc: jolsa@redhat.com Cc: stable@kernel.org Link: https://lkml.kernel.org/r/20190314130705.441549378@infradead.org --- arch/x86/events/intel/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 35102ecdfc8d5..92dfeb343a6ae 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -3410,7 +3410,7 @@ tfa_get_event_constraints(struct cpu_hw_events *cpuc, int idx, /* * Without TFA we must not use PMC3. */ - if (!allow_tsx_force_abort && test_bit(3, c->idxmsk)) { + if (!allow_tsx_force_abort && test_bit(3, c->idxmsk) && idx >= 0) { c = dyn_constraint(cpuc, c, idx); c->idxmsk64 &= ~(1ULL << 3); c->weight--; -- cgit v1.2.3