This is a note to let you know that I've just added the patch titled
btrfs: handle invalid root reference found in may_destroy_subvol()
to the 4.19-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-handle-invalid-root-reference-found-in-may_des.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 92fc3855e3d0b44364e5b32c9ec0f0edb8b16010
Author: David Sterba <dsterba@xxxxxxxx>
Date: Wed Jan 24 22:58:01 2024 +0100
btrfs: handle invalid root reference found in may_destroy_subvol()
[ Upstream commit 6fbc6f4ac1f4907da4fc674251527e7dc79ffbf6 ]
The may_destroy_subvol() looks up a root by a key, allowing to do an
inexact search when key->offset is -1. It's never expected to find such
item, as it would break the allowed range of a root id.
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7f675862ffb0e..15ebebed40056 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4296,7 +4296,14 @@ static noinline int may_destroy_subvol(struct btrfs_root *root)
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret < 0)
goto out;
- BUG_ON(ret == 0);
+ if (ret == 0) {
+ /*
+ * Key with offset -1 found, there would have to exist a root
+ * with such id, but this is out of valid range.
+ */
+ ret = -EUCLEAN;
+ goto out;
+ }
ret = 0;
if (path->slots[0] > 0) {
