[PATCH 6.1 142/473] drivers/perf: hisi: hns3: Fix out-of-bound access when valid event group

Greg Kroah-Hartman
2024-06-06T14:14:48Z

From: Junhao He <hejunhao3@huawei.com>

[ 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@huawei.com>
Signed-off-by: Hao Chen <chenhao418@huawei.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Jijie Shao <shaojijie@huawei.com>
Link: https://lore.kernel.org/r/20240425124627.13764-3-hejunhao3@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/perf/hisilicon/hns3_pmu.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

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)
--
2.43.0