CVE-2023-54043 iommufd: Do not add the same hwpt to the ioas->hwpt_list twice
A logic error in the Linux kernel iommufd subsystem can corrupt a linked list, potentially leading to system instability or 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-2023-54043?
CVE-2023-54043 is a high-severity memory corruption 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:
iommufd: Do not add the same hwpt to the ioas->hwpt_list twice
The hwpt is added to the hwpt_list only during its creation, it is never added again. This hunk is some missed leftover from rework. Adding it twice will corrupt the linked list in some cases.
It effects HWPT specific attachment, which is something the test suite cannot cover until we can create a legitimate struct device with a non-system iommu "driver" (ie we need the bus removed from the iommu code)
Which versions are affected by CVE-2023-54043?
How do I fix CVE-2023-54043?
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-2023-54043 being exploited?
There is no known exploitation of CVE-2023-54043 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54043, GHSA-hwvv-764m-j5cv, UBUNTU-CVE-2023-54043.