4.20-stable review patch. If anyone has any objections, please let me know.
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From: Peter Zijlstra peterz@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 tonyj@suse.com Reported-by: "DSouza, Nelson" nelson.dsouza@intel.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Tested-by: Tony Jones tonyj@suse.com Tested-by: "DSouza, Nelson" nelson.dsouza@intel.com Cc: eranian@google.com Cc: jolsa@redhat.com Cc: stable@kernel.org Link: https://lkml.kernel.org/r/20190314130705.441549378@infradead.org Signed-off-by: Greg Kroah-Hartman gregkh@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--;