Messages in this thread Patch in this message | | | From | "DSouza, Nelson" <> | Subject | RE: [PATCH 4.14 31/34] perf/x86/intel: Fix memory corruption | Date | Mon, 18 Mar 2019 20:29:37 +0000 |
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With the patch, the kernel crash is not seen on 4.14, 4.19 and 4.20 kernels.
-----Original Message----- From: DSouza, Nelson Sent: Monday, March 18, 2019 11:21 AM To: 'Greg Kroah-Hartman' <gregkh@linuxfoundation.org>; linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org; Tony Jones <tonyj@suse.com>; Peter Zijlstra (Intel) <peterz@infradead.org>; Thomas Gleixner <tglx@linutronix.de>; eranian@google.com; jolsa@redhat.com; stable@kernel.org Subject: RE: [PATCH 4.14 31/34] perf/x86/intel: Fix memory corruption
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@linuxfoundation.org] Sent: Monday, March 18, 2019 2:26 AM To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>; stable@vger.kernel.org; Tony Jones <tonyj@suse.com>; DSouza, Nelson <nelson.dsouza@intel.com>; Peter Zijlstra (Intel) <peterz@infradead.org>; Thomas Gleixner <tglx@linutronix.de>; eranian@google.com; jolsa@redhat.com; stable@kernel.org 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.
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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 @@ -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--;
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