From: Pawel Moll <pawel.moll@xxxxxxx> This patch has been added to the 3.18 stable tree. If you have any objections, please let us know. =============== [ Upstream commit b7c1beb278e8e3dc664ed3df3fc786db126120a9 ] 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> Cc: stable@xxxxxxxxxxxxxxx # 3.17+ Signed-off-by: Pawel Moll <pawel.moll@xxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> --- drivers/bus/arm-ccn.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/bus/arm-ccn.c b/drivers/bus/arm-ccn.c index 60397ec..bf2092c 100644 --- a/drivers/bus/arm-ccn.c +++ b/drivers/bus/arm-ccn.c @@ -804,6 +804,10 @@ static void arm_ccn_pmu_xp_dt_config(struct perf_event *event, int enable) 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 -- 2.7.4 -- 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