This is a note to let you know that I've just added the patch titled drivers/perf: hisi: hns3: Fix out-of-bound access when valid event group to the 6.8-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: drivers-perf-hisi-hns3-fix-out-of-bound-access-when-.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c71ea91d874156b9cb7fd597b1150ef84bfe2953 Author: Junhao He <hejunhao3@xxxxxxxxxx> Date: Thu Apr 25 20:46:26 2024 +0800 drivers/perf: hisi: hns3: Fix out-of-bound access when valid event group [ Upstream commit 81bdd60a3d1d3b05e6cc6674845afb1694dd3a0e ] The perf tool allows users to create event groups through following cmd [1], but the driver does not check whether the array index is out of bounds when writing data to the event_group array. If the number of events in an event_group is greater than HNS3_PMU_MAX_HW_EVENTS, the memory write overflow of event_group array occurs. Add array index check to fix the possible array out of bounds violation, and return directly when write new events are written to array bounds. There are 9 different events in an event_group. [1] perf stat -e '{pmu/event1/, ... ,pmu/event9/} Fixes: 66637ab137b4 ("drivers/perf: hisi: add driver for HNS3 PMU") Signed-off-by: Junhao He <hejunhao3@xxxxxxxxxx> Signed-off-by: Hao Chen <chenhao418@xxxxxxxxxx> Acked-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Reviewed-by: Jijie Shao <shaojijie@xxxxxxxxxx> Link: https://lore.kernel.org/r/20240425124627.13764-3-hejunhao3@xxxxxxxxxx Signed-off-by: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/perf/hisilicon/hns3_pmu.c b/drivers/perf/hisilicon/hns3_pmu.c index 16869bf5bf4cc..cbdd53b0a0342 100644 --- a/drivers/perf/hisilicon/hns3_pmu.c +++ b/drivers/perf/hisilicon/hns3_pmu.c @@ -1085,15 +1085,27 @@ static bool hns3_pmu_validate_event_group(struct perf_event *event) return false; for (num = 0; num < counters; num++) { + /* + * If we find a related event, then it's a valid group + * since we don't need to allocate a new counter for it. + */ if (hns3_pmu_cmp_event(event_group[num], sibling)) break; } + /* + * Otherwise it's a new event but if there's no available counter, + * fail the check since we cannot schedule all the events in + * the group simultaneously. + */ + if (num == HNS3_PMU_MAX_HW_EVENTS) + return false; + if (num == counters) event_group[counters++] = sibling; } - return counters <= HNS3_PMU_MAX_HW_EVENTS; + return true; } static u32 hns3_pmu_get_filter_condition(struct perf_event *event)