CVE-2023-54140 nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
A local attacker with a corrupted disk image can trigger a kernel warning and panic in the nilfs2 filesystem, causing 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-2023-54140?
CVE-2023-54140 is a high-severity vulnerability in Linux, published on 24 Dec 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:
nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
A syzbot stress test using a corrupted disk image reported that mark_buffer_dirty() called from __nilfs_mark_inode_dirty() or nilfs_palloc_commit_alloc_entry() may output a kernel warning, and can panic if the kernel is booted with panic_on_warn.
This is because nilfs2 keeps buffer pointers in local structures for some metadata and reuses them, but such buffers may be forcibly discarded by nilfs_clear_dirty_page() in some critical situations.
This issue is reported to appear after commit 28a65b49eb53 ("nilfs2: do not write dirty data after degenerating to read-only"), but the issue has potentially existed before.
Fix this issue by checking the uptodate flag when attempting to reuse an internally held buffer, and reloading the metadata instead of reusing the buffer if the flag was lost.
Which versions are affected by CVE-2023-54140?
How do I fix CVE-2023-54140?
Apply the vendor's patch.
Is CVE-2023-54140 being exploited?
There is no known exploitation of CVE-2023-54140 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54140, DEBIAN-CVE-2023-54140, GHSA-8vr5-q73g-2w33, UBUNTU-CVE-2023-54140.