This is a note to let you know that I've just added the patch titled btrfs: send: handle path ref underflow in header iterate_inode_ref() to the 5.15-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-send-handle-path-ref-underflow-in-header-itera.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e12129979dea129e7f04a91533e4109b6cbbe40a Author: David Sterba <dsterba@xxxxxxxx> Date: Tue Feb 6 22:47:13 2024 +0100 btrfs: send: handle path ref underflow in header iterate_inode_ref() [ Upstream commit 3c6ee34c6f9cd12802326da26631232a61743501 ] Change BUG_ON to proper error handling if building the path buffer fails. The pointers are not printed so we don't accidentally leak kernel addresses. Signed-off-by: David Sterba <dsterba@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 9900f879fa346..f1ef176a64242 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -976,7 +976,15 @@ static int iterate_inode_ref(struct btrfs_root *root, struct btrfs_path *path, ret = PTR_ERR(start); goto out; } - BUG_ON(start < p->buf); + if (unlikely(start < p->buf)) { + btrfs_err(root->fs_info, + "send: path ref buffer underflow for key (%llu %u %llu)", + found_key->objectid, + found_key->type, + found_key->offset); + ret = -EINVAL; + goto out; + } } p->start = start; } else {