[PATCH v4 1/7] md/raid10: fix r10bio leak in raid10_write_request() error paths

[Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>]

When raid10_write_request() fails because REQ_NOWAIT is set, the
allocated r10_bio is not freed before returning, resulting in a memory
leak. Free r10_bio before returning from the REQ_NOWAIT error paths.

Fixes: c9aa889b035f ("md: raid10 add nowait support")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Closes: https://lore.kernel.org/linux-raid/20260613184042.BCEC01F000E9@smtp.kernel.org/
Signed-off-by: Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
---
Changes in v4:
 - No changes.
 - Link to v3: https://lore.kernel.org/linux-raid/20260708101341.473750-2-abd.masalkhi@gmail.com/

Changes in v3:
 - No changes.
 - Link to v2: https://lore.kernel.org/linux-raid/20260628142420.1051027-2-abd.masalkhi@gmail.com/

Changes in v2:
 - No changes.
 - Link to v1: https://lore.kernel.org/linux-raid/20260623072456.333437-2-abd.masalkhi@gmail.com/
---
 drivers/md/raid10.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 0a3cfdd3f5df..bd322eccdc3f 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1365,6 +1365,7 @@ static bool raid10_write_request(struct mddev *mddev, struct bio *bio,
 		/* Bail out if REQ_NOWAIT is set for the bio */
 		if (bio->bi_opf & REQ_NOWAIT) {
 			bio_wouldblock_error(bio);
+			free_r10bio(r10_bio);
 			return false;
 		}
 		for (;;) {
@@ -1398,6 +1399,7 @@ static bool raid10_write_request(struct mddev *mddev, struct bio *bio,
 		if (bio->bi_opf & REQ_NOWAIT) {
 			allow_barrier(conf);
 			bio_wouldblock_error(bio);
+			free_r10bio(r10_bio);
 			return false;
 		}
 		mddev_add_trace_msg(conf->mddev,
-- 
2.43.0