This is a note to let you know that I've just added the patch titled btrfs: export: handle invalid inode or root reference in btrfs_get_parent() to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: btrfs-export-handle-invalid-inode-or-root-reference-.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e4e1bcd8d60754c092e2237ceabcec213e4366b3 Author: David Sterba <dsterba@xxxxxxxx> Date: Fri Jan 19 21:19:18 2024 +0100 btrfs: export: handle invalid inode or root reference in btrfs_get_parent() [ Upstream commit 26b66d1d366a375745755ca7365f67110bbf6bd5 ] 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@xxxxxxxxxxxxxx> Reviewed-by: Anand Jain <anand.jain@xxxxxxxxxx> Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/btrfs/export.c b/fs/btrfs/export.c index fab7eb76e53b2..58b0f04d7123f 100644 --- a/fs/btrfs/export.c +++ b/fs/btrfs/export.c @@ -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;