CVE-2026-80880 IB/mlx5: Properly support implicit ODP rereg_mr
A race condition in the Linux kernel's mlx5 InfiniBand driver allows local attackers to cause denial of service or escalate privileges via implicit ODP memory registration.
- 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-2026-80880?
CVE-2026-80880 is a vulnerability in Linux, published on 4 Sep 2026. 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:
IB/mlx5: Properly support implicit ODP rereg_mr
Due to all the child mkeys in the implicit ODP configuration we cannot change anything in place for the parent mkey. Instead the whole thing needs to be rebuilt if any change is requested. If the user does not specify a translation then force the implicit values which will then fall through the logic into mlx5_ib_reg_user_mr() to allocate a completely new MR.
Since implicit children were also touching the mr->pd, this removes another case where the access was racy.
Which versions are affected by CVE-2026-80880?
How do I fix CVE-2026-80880?
Apply the vendor's patch.
Is CVE-2026-80880 being exploited?
There is no known exploitation of CVE-2026-80880 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80880, DEBIAN-CVE-2026-80880, GHSA-v3r8-hwvc-wv26, UBUNTU-CVE-2026-80880.