CVE-2023-54317 dm flakey: don't corrupt the zero page
A flaw in the Linux kernel dm-flakey target corrupts the zero page, causing userspace crashes and 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-2023-54317?
CVE-2023-54317 is a high-severity memory corruption vulnerability in Linux, published on 30 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:
dm flakey: don't corrupt the zero page
When we need to zero some range on a block device, the function __blkdev_issue_zero_pages submits a write bio with the bio vector pointing to the zero page. If we use dm-flakey with corrupt bio writes option, it will corrupt the content of the zero page which results in crashes of various userspace programs. Glibc assumes that memory returned by mmap is zeroed and it uses it for calloc implementation; if the newly mapped memory is not zeroed, calloc will return non-zeroed memory.
Fix this bug by testing if the page is equal to ZERO_PAGE(0) and avoiding the corruption in this case.
Which versions are affected by CVE-2023-54317?
How do I fix CVE-2023-54317?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2023-54317 being exploited?
There is no known exploitation of CVE-2023-54317 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54317, DEBIAN-CVE-2023-54317, GHSA-8m2v-q2gj-8gq3, UBUNTU-CVE-2023-54317.