ext4: cleanup in-core orphan list if ext4_truncate() failed to get a transaction handle

In ext4_orphan_cleanup(), if ext4_truncate() failed to get a transaction
handle, it didn't remove the inode from the in-core orphan list, which
may probably trigger below error dump in ext4_destroy_inode() during the
final iput() and could lead to memory corruption on the later orphan
list changes.

 EXT4-fs (sda): Inode 6291467 (00000000b8247c67): orphan list check failed!
 00000000b8247c67: 0001f30a 00000004 00000000 00000023  ............#...
 00000000e24cde71: 00000006 014082a3 00000000 00000000  ......@.........
 0000000072c6a5ee: 00000000 00000000 00000000 00000000  ................
 ...

This patch fix this by cleanup in-core orphan list manually if
ext4_truncate() return error.

Cc: stable@kernel.org
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210507071904.160808-1-yi.zhang@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/super.c

@@ -3101,8 +3101,15 @@ static void ext4_orphan_cleanup(struct super_block *sb,
 			inode_lock(inode);
 			truncate_inode_pages(inode->i_mapping, inode->i_size);
 			ret = ext4_truncate(inode);
-			if (ret)
+			if (ret) {
+				/*
+				 * We need to clean up the in-core orphan list
+				 * manually if ext4_truncate() failed to get a
+				 * transaction handle.
+				 */
+				ext4_orphan_del(NULL, inode);
 				ext4_std_error(inode->i_sb, ret);
+			}
 			inode_unlock(inode);
 			nr_truncates++;
 		} else {