From: Aditya Pakki <pakki001@umn.edu>
Date: Mon, 4 Mar 2019 16:48:54 -0600
Subject: [PATCH] md: Fix failed allocation of md_register_thread
Git-commit: e406f12dde1a8375d77ea02d91f313fb1a9c6aec
Patch-mainline: v5.1
References: git-fixes

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@vger.kernel.org # v3.16+
Acked-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Song Liu <songliubraving@fb.com>

---
 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
@@ -3993,6 +3993,8 @@ 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
@@ -7384,6 +7384,8 @@ 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 */