6.6-stable review patch. If anyone has any objections, please let me know.
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From: Leo Yan leo.yan@arm.com
[ Upstream commit 8a55c161f7f9c1aa1c70611b39830d51c83ef36d ]
When the TRBE driver fails to allocate a buffer, it currently returns the error code "-ENOMEM". However, the caller etm_setup_aux() only checks for a NULL pointer, so it misses the error. As a result, the driver continues and eventually causes a kernel panic.
Fix this by returning a NULL pointer from arm_trbe_alloc_buffer() on allocation failures. This allows that the callers can properly handle the failure.
Fixes: 3fbf7f011f24 ("coresight: sink: Add TRBE driver") Reported-by: Tamas Zsoldos tamas.zsoldos@arm.com Signed-off-by: Leo Yan leo.yan@arm.com Reviewed-by: James Clark james.clark@linaro.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Link: https://lore.kernel.org/r/20250904-cs_etm_auxsetup_fix_error_handling-v2-1-a... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwtracing/coresight/coresight-trbe.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 7f91b1ffe66a5..a564bd5c8b62d 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -744,12 +744,12 @@ static void *arm_trbe_alloc_buffer(struct coresight_device *csdev,
buf = kzalloc_node(sizeof(*buf), GFP_KERNEL, trbe_alloc_node(event)); if (!buf) - return ERR_PTR(-ENOMEM); + return NULL;
pglist = kcalloc(nr_pages, sizeof(*pglist), GFP_KERNEL); if (!pglist) { kfree(buf); - return ERR_PTR(-ENOMEM); + return NULL; }
for (i = 0; i < nr_pages; i++) @@ -759,7 +759,7 @@ static void *arm_trbe_alloc_buffer(struct coresight_device *csdev, if (!buf->trbe_base) { kfree(pglist); kfree(buf); - return ERR_PTR(-ENOMEM); + return NULL; } buf->trbe_limit = buf->trbe_base + nr_pages * PAGE_SIZE; buf->trbe_write = buf->trbe_base;