[PATCH AUTOSEL 4.19 10/11] btrfs: send: handle path ref underflow in header iterate_inode_ref()

From: Sasha Levin
Date: Fri Mar 29 2024 - 09:28:58 EST


From: David Sterba <dsterba@xxxxxxxx>

[ 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>
---
fs/btrfs/send.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 0c86409a316e8..e3b6ca9176afe 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -958,7 +958,15 @@ 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 {
--
2.43.0