4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Peter Zijlstra <pet...@infradead.org>
commit ede271b059463731cbd6dffe55ffd70d7dbe8392 upstream.
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 <to...@suse.com>
Reported-by: "DSouza, Nelson" <nelson.dso...@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Tested-by: Tony Jones <to...@suse.com>
Tested-by: "DSouza, Nelson" <nelson.dso...@intel.com>
Cc: eran...@google.com
Cc: jo...@redhat.com
Cc: sta...@kernel.org
Link: https://lkml.kernel.org/r/20190314130705.441549...@infradead.org
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.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
@@ -3398,7 +3398,7 @@ 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--;
