[PATCH 6.1 141/473] drivers/perf: hisi_pcie: Fix out-of-bound access when valid event group

Greg Kroah-Hartman
2024-06-06T14:14:36Z

From: Junhao He <hejunhao3@huawei.com>

[ Upstream commit 77fce82678ea5fd51442e62febec2004f79e041b ]

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 HISI_PCIE_MAX_COUNTERS, 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: 8404b0fbc7fb ("drivers/perf: hisi: Add driver for HiSilicon PCIe PMU")
Signed-off-by: Junhao He <hejunhao3@huawei.com>
Reviewed-by: Jijie Shao <shaojijie@huawei.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20240425124627.13764-2-hejunhao3@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/perf/hisilicon/hisi_pcie_pmu.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/perf/hisilicon/hisi_pcie_pmu.c b/drivers/perf/hisilicon/hisi_pcie_pmu.c
index c4c1cd269c577..49f2d69c119df 100644
--- a/drivers/perf/hisilicon/hisi_pcie_pmu.c
+++ b/drivers/perf/hisilicon/hisi_pcie_pmu.c
@@ -326,15 +326,27 @@ static bool hisi_pcie_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 (hisi_pcie_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 == HISI_PCIE_MAX_COUNTERS)
+ return false;
+
if (num == counters)
event_group[counters++] = sibling;
}

- return counters <= HISI_PCIE_MAX_COUNTERS;
+ return true;
}

static int hisi_pcie_pmu_event_init(struct perf_event *event)
--
2.43.0