Through:
validate_event()
x86_pmu.get_event_constraints(.idx=-1)
tfa_get_event_constraints()
dyn_constraint()
We use cpuc->constraint_list[-1], 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.
Reported-by: Tony Jones <to...@suse.com>
Reported-by: "DSouza, Nelson" <nelson.dso...@intel.com>
Tested-by: Tony Jones <to...@suse.com>
Tested-by: "DSouza, Nelson" <nelson.dso...@intel.com>
Cc: sta...@kernel.org
Fixes: 400816f60c54 ("perf/x86/intel: Implement support for TSX Force Abort")
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
---
arch/x86/events/intel/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- 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_
/*
* 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--;
