fs/affs: release old buffer head on error path

stable inclusion
from stable-5.10.20
commit 885a2d24c219354639306c63b5e658fdc25ebbb5
bugzilla: 50608

--------------------------------

commit 70779b89 upstream.

The reference count of the old buffer head should be decremented on path
that fails to get the new buffer head.

Fixes: 6b465766 ("fs/affs: add rename exchange")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: NPan Bian <bianpan2016@163.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/affs/namei.c

@@ -460,8 +460,10 @@ affs_xrename(struct inode *old_dir, struct dentry *old_dentry,
 		return -EIO;
 
 	bh_new = affs_bread(sb, d_inode(new_dentry)->i_ino);
-	if (!bh_new)
+	if (!bh_new) {
+		affs_brelse(bh_old);
 		return -EIO;
+	}
 
 	/* Remove old header from its parent directory. */
 	affs_lock_dir(old_dir);