ext4: fix buffer leak in ext4_xattr_get_block() on error path

commit ecaaf408 upstream.

Fixes: dec214d0 ("ext4: xattr inode deduplication")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org # 4.13
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/ext4/xattr.c

@@ -2281,8 +2281,10 @@ static struct buffer_head *ext4_xattr_get_block(struct inode *inode)
 	if (!bh)
 		return ERR_PTR(-EIO);
 	error = ext4_xattr_check_block(inode, bh);
-	if (error)
+	if (error) {
+		brelse(bh);
 		return ERR_PTR(error);
+	}
 	return bh;
 }