From 104212471b1c1817b311771d817fb692af983173 Mon Sep 17 00:00:00 2001
From: Wentao_Liang <Wentao_Liang_g@163.com>
Date: Thu, 28 Jul 2022 19:39:19 +0800
Subject: [PATCH] drivers:md:fix a potential use-after-free bug
Git-commit: 104212471b1c1817b311771d817fb692af983173
Patch-mainline: v6.0-rc1
References: git-fixes

In line 2884, "raid5_release_stripe(sh);" drops the reference to sh and
may cause sh to be released. However, sh is subsequently used in lines
2886 "if (sh->batch_head && sh != sh->batch_head)". This may result in an
use-after-free bug.

It can be fixed by moving "raid5_release_stripe(sh);" to the bottom of
the function.

Signed-off-by: Wentao_Liang <Wentao_Liang_g@163.com>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/raid5.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 8d10b190bdbb..860c45c10a57 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2952,10 +2952,10 @@ static void raid5_end_write_request(struct bio *bi)
 	if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags))
 		clear_bit(R5_LOCKED, &sh->dev[i].flags);
 	set_bit(STRIPE_HANDLE, &sh->state);
-	raid5_release_stripe(sh);
 
 	if (sh->batch_head && sh != sh->batch_head)
 		raid5_release_stripe(sh->batch_head);
+	raid5_release_stripe(sh);
 }
 
 static void raid5_error(struct mddev *mddev, struct md_rdev *rdev)
-- 
2.35.3