This is a note to let you know that I've just added the patch titled bus: arm-ccn: Do not attempt to configure XPs for cycle counter to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bus-arm-ccn-do-not-attempt-to-configure-xps-for-cycle-counter.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b7c1beb278e8e3dc664ed3df3fc786db126120a9 Mon Sep 17 00:00:00 2001 From: Pawel Moll <pawel.moll@xxxxxxx> Date: Fri, 5 Aug 2016 15:07:10 +0100 Subject: bus: arm-ccn: Do not attempt to configure XPs for cycle counter From: Pawel Moll <pawel.moll@xxxxxxx> commit b7c1beb278e8e3dc664ed3df3fc786db126120a9 upstream. Fuzzing the CCN perf driver revealed a small but definitely dangerous mistake in the event setup code. When a cycle counter is requested, the driver should not reconfigure the events bus at all, otherwise it will corrupt (in most but the simplest cases) its configuration and may end up accessing XP array out of its bounds and corrupting control registers. Reported-by: Mark Rutland <mark.rutland@xxxxxxx> Reviewed-by: Mark Rutland <mark.rutland@xxxxxxx> Tested-by: Mark Rutland <mark.rutland@xxxxxxx> Signed-off-by: Pawel Moll <pawel.moll@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/bus/arm-ccn.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -895,6 +895,10 @@ static void arm_ccn_pmu_xp_dt_config(str struct arm_ccn_component *xp; u32 val, dt_cfg; + /* Nothing to do for cycle counter */ + if (hw->idx == CCN_IDX_PMU_CYCLE_COUNTER) + return; + if (CCN_CONFIG_TYPE(event->attr.config) == CCN_TYPE_XP) xp = &ccn->xp[CCN_CONFIG_XP(event->attr.config)]; else Patches currently in stable-queue which might be from pawel.moll@xxxxxxx are queue-4.4/bus-arm-ccn-fix-xp-watchpoint-settings-bitmask.patch queue-4.4/bus-arm-ccn-do-not-attempt-to-configure-xps-for-cycle-counter.patch queue-4.4/bus-arm-ccn-fix-pmu-handling-of-mn.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html