[PATCH 6.18 054/641] md/raid1: fix memory leak in raid1_run()

Greg Kroah-Hartman
2026-02-25T01:42:42Z

6.18-stable review patch. If anyone has any objections, please let me know.

------------------

From: Zilin Guan <zilin@seu.edu.cn>

[ Upstream commit 6abc7d5dcf0ee0f85e16e41c87fbd06231f28753 ]

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.

Link: https://lore.kernel.org/linux-raid/20260126071533.606263-1-zilin@seu.edu.cn
Fixes: 97894f7d3c29 ("md/raid1: use the atomic queue limit update APIs")
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Reviewed-by: Li Nan <linan122@huawei.com>
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/md/raid1.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 592a402330047..ce7fd68869566 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -3253,6 +3253,7 @@ 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;
--
2.51.0