5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: David Sterba <dsterba@xxxxxxxx>
[ 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>
---
fs/btrfs/inode.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1f99d7dced17a..4bf28f74605fd 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3918,7 +3918,14 @@ 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) {
--
2.43.0
