CVE-2023-52569 btrfs: remove BUG() after failure to insert delayed dir index item
A local attacker can trigger a kernel panic in the Btrfs filesystem by causing a delayed directory index insertion failure, resulting in a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-52569?
CVE-2023-52569 is a medium-severity denial of service vulnerability in Linux kernel, published on 2 Mar 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
btrfs: remove BUG() after failure to insert delayed dir index item
Instead of calling BUG() when we fail to insert a delayed dir index item into the delayed node's tree, we can just release all the resources we have allocated/acquired before and return the error to the caller. This is fine because all existing call chains undo anything they have done before calling btrfs_insert_delayed_dir_index() or BUG_ON (when creating pending snapshots in the transaction commit path).
So remove the BUG() call and do proper error handling.
This relates to a syzbot report linked below, but does not fix it because it only prevents hitting a BUG(), it does not fix the issue where somehow we attempt to use twice the same index number for different index items.
Weakness: CWE-617
Which versions are affected by CVE-2023-52569?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-52569?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-52569 being exploited?
There is no known exploitation of CVE-2023-52569 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-55779, BELL-CVE-2023-52569, DEBIAN-CVE-2023-52569, GHSA-484w-f535-whcj, ROOT-OS-UBUNTU-2204-CVE-2023-52569, UBUNTU-CVE-2023-52569.