ext4: fix buffer leak in ext4_expand_extra_isize_ea() on error path

Fixes: de05ca8526 ("ext4: move call to ext4_error() into ...")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org # 4.17

fs/ext4/xattr.c

@@ -2698,7 +2698,6 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
 			       struct ext4_inode *raw_inode, handle_t *handle)
 {
 	struct ext4_xattr_ibody_header *header;
-	struct buffer_head *bh;
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
 	static unsigned int mnt_count;
 	size_t min_offs;
@@ -2739,13 +2738,17 @@ retry:
 	 * EA block can hold new_extra_isize bytes.
 	 */
 	if (EXT4_I(inode)->i_file_acl) {
+		struct buffer_head *bh;
+
 		bh = sb_bread(inode->i_sb, EXT4_I(inode)->i_file_acl);
 		error = -EIO;
 		if (!bh)
 			goto cleanup;
 		error = ext4_xattr_check_block(inode, bh);
-		if (error)
+		if (error) {
+			brelse(bh);
 			goto cleanup;
+		}
 		base = BHDR(bh);
 		end = bh->b_data + bh->b_size;
 		min_offs = end - base;