5.0-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nikolay Borisov <nborisov@xxxxxxxx>
commit 7ff2c2a1a71e83f74574b8001ea88deb3c166ad7 upstream.
If 'cur_level' is 7 then the bound checking at the top of the function
will actually pass. Later on, it's possible to dereference
ds_path->nodes[cur_level+1] which will be an out of bounds.
The correct check will be cur_level >= BTRFS_MAX_LEVEL - 1 .
Fixes-coverty-id: 1440918
Fixes-coverty-id: 1440911
Fixes: ea49f3e73c4b ("btrfs: qgroup: Introduce function to find all new tree blocks of reloc tree")
CC: stable@xxxxxxxxxxxxxxx # 4.20+
Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>
Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/qgroup.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1917,8 +1917,8 @@ static int qgroup_trace_new_subtree_bloc
int i;
/* Level sanity check */
- if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL ||
- root_level < 0 || root_level >= BTRFS_MAX_LEVEL ||
+ if (cur_level < 0 || cur_level >= BTRFS_MAX_LEVEL - 1 ||
+ root_level < 0 || root_level >= BTRFS_MAX_LEVEL - 1 ||
root_level < cur_level) {
btrfs_err_rl(fs_info,
"%s: bad levels, cur_level=%d root_level=%d",
