From: Christian Brauner <brauner@kernel.org>
Date: Mon, 28 Aug 2023 11:26:23 +0000 (+0200)
Subject: super: move lockdep assert
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=345a5c4a0b635fa3fc658e6e0cd7fd2217c667cd;p=linux.git

super: move lockdep assert

Fix braino and move the lockdep assertion after put_super() otherwise we
risk a use-after-free.

Fixes: 2c18a63b760a ("super: wait until we passed kill super")
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Message-Id: <20230828-vfs-super-fixes-v1-1-b37a4a04a88f@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
---

diff --git a/fs/super.c b/fs/super.c
index ef87103e2a519..779247eb219cb 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -570,8 +570,8 @@ static bool grab_super_dead(struct super_block *sb)
 		return true;
 	}
 	wait_var_event(&sb->s_flags, wait_dead(sb));
-	put_super(sb);
 	lockdep_assert_not_held(&sb->s_umount);
+	put_super(sb);
 	return false;
 }