[PATCH 4.9 112/118] md: Fix failed allocation of md_register_thread

[Greg Kroah-Hartman]

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

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

From: Aditya Pakki <pakki001@xxxxxxx>

commit e406f12dde1a8375d77ea02d91f313fb1a9c6aec upstream.

mddev->sync_thread can be set to NULL on kzalloc failure downstream.
The patch checks for such a scenario and frees allocated resources.

Committer node:

Added similar fix to raid5.c, as suggested by Guoqing.

Cc: stable@xxxxxxxxxxxxxxx # v3.16+
Acked-by: Guoqing Jiang <gqjiang@xxxxxxxx>
Signed-off-by: Aditya Pakki <pakki001@xxxxxxx>
Signed-off-by: Song Liu <songliubraving@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/md/raid10.c |    2 ++
 drivers/md/raid5.c  |    2 ++
 2 files changed, 4 insertions(+)

--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -3798,6 +3798,8 @@ static int raid10_run(struct mddev *mdde
 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
 		mddev->sync_thread = md_register_thread(md_do_sync, mddev,
 							"reshape");
+		if (!mddev->sync_thread)
+			goto out_free_conf;
 	}
 
 	return 0;
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6977,6 +6977,8 @@ static int raid5_run(struct mddev *mddev
 		set_bit(MD_RECOVERY_RUNNING, &mddev->recovery);
 		mddev->sync_thread = md_register_thread(md_do_sync, mddev,
 							"reshape");
+		if (!mddev->sync_thread)
+			goto abort;
 	}
 
 	/* Ok, everything is just fine now */