Hi Greg, I was able to reproduce the kernel crash on 4.14, 4.19 and 4.20 kernels. Will apply your patches and re-test. Thanks, Nelson -----Original Message----- From: Greg Kroah-Hartman [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] Sent: Monday, March 18, 2019 2:26 AM To: linux-kernel@xxxxxxxxxxxxxxx Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; stable@xxxxxxxxxxxxxxx; Tony Jones <tonyj@xxxxxxxx>; DSouza, Nelson <nelson.dsouza@xxxxxxxxx>; Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>; Thomas Gleixner <tglx@xxxxxxxxxxxxx>; eranian@xxxxxxxxxx; jolsa@xxxxxxxxxx; stable@xxxxxxxxxx Subject: [PATCH 4.14 31/34] perf/x86/intel: Fix memory corruption 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Zijlstra <peterz@xxxxxxxxxxxxx> 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@xxxxxxxx> Reported-by: "DSouza, Nelson" <nelson.dsouza@xxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Tested-by: Tony Jones <tonyj@xxxxxxxx> Tested-by: "DSouza, Nelson" <nelson.dsouza@xxxxxxxxx> Cc: eranian@xxxxxxxxxx Cc: jolsa@xxxxxxxxxx Cc: stable@xxxxxxxxxx Link: https://lkml.kernel.org/r/20190314130705.441549378@xxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -3262,7 +3262,7 @@ 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--;
