[PATCH] md/raid1: fix memory leak in raid1_run()

[Zilin Guan]

raid1_run() calls setup_conf() which registers a thread via
md_register_thread(). If raid1_set_limits() fails, the previously
registered thread is not unregistered, resulting in a memory leak
of the md_thread structure and the thread resource itself.

Add md_unregister_thread() to the error path to properly cleanup
the thread, which aligns with the error handling logic of other paths
in this function.

Compile tested only. Issue found using a prototype static analysis tool
and code review.

Fixes: 97894f7d3c29 ("md/raid1: use the atomic queue limit update APIs")
Signed-off-by: Zilin Guan <zilin@xxxxxxxxxx>
---
 drivers/md/raid1.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 57d50465eed1..cc9914bd15c1 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -3254,6 +3254,7 @@ static int raid1_run(struct mddev *mddev)
 	if (!mddev_is_dm(mddev)) {
 		ret = raid1_set_limits(mddev);
 		if (ret) {
+			md_unregister_thread(mddev, &conf->thread);
 			if (!mddev->private)
 				raid1_free(mddev, conf);
 			return ret;
-- 
2.34.1