CVE-2023-53429 btrfs: don't check PageError in __extent_writepage
A race condition in the Linux kernel's btrfs filesystem allows error bits to leak, potentially causing system instability or crashes.
- 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-2023-53429?
CVE-2023-53429 is a high-severity vulnerability in Linux kernel, published on 18 Sep 2025. 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: don't check PageError in __extent_writepage
__extent_writepage currenly sets PageError whenever any error happens, and the also checks for PageError to decide if to call error handling. This leads to very unclear responsibility for cleaning up on errors. In the VM and generic writeback helpers the basic idea is that once I/O is fired off all error handling responsibility is delegated to the end I/O handler. But if that end I/O handler sets the PageError bit, and the submitter checks it, the bit could in some cases leak into the submission context for fast enough I/O.
Fix this by simply not checking PageError and just using the local ret variable to check for submission errors. This also fundamentally solves the long problem documented in a comment in __extent_writepage by never leaking the error bit into the submission context.
Which versions are affected by CVE-2023-53429?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53429?
Apply the vendor's patch.
Is CVE-2023-53429 being exploited?
There is no known exploitation of CVE-2023-53429 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-71921, BELL-CVE-2023-53429, DEBIAN-CVE-2023-53429, GHSA-95qf-frmh-4g6j, ROOT-OS-DEBIAN-11-CVE-2023-53429, ROOT-OS-DEBIAN-12-CVE-2023-53429 and 2 more.