btrfs: export: handle invalid inode or root reference in btrfs_get_parent()

[ Upstream commit 26b66d1d36 ]

The get_parent handler looks up a parent of a given dentry, this can be
either a subvolume or a directory. The search is set up with offset -1
but it's never expected to find such item, as it would break allowed
range of inode number or a root id. This means it's a corruption (ext4
also returns this error code).

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
David Sterba 2024-01-19 21:19:18 +01:00 committed by Greg Kroah-Hartman
parent d1ffa4ae2d
commit a83c1f67a0
1 changed files with 8 additions and 1 deletions

View File

@ -161,8 +161,15 @@ struct dentry *btrfs_get_parent(struct dentry *child)
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto fail;
if (ret == 0) {
/*
* Key with offset of -1 found, there would have to exist an
* inode with such number or a root with such id.
*/
ret = -EUCLEAN;
goto fail;
}
BUG_ON(ret == 0); /* Key with offset of -1 found */
if (path->slots[0] == 0) {
ret = -ENOENT;
goto fail;