CVE-2026-74334 RDMA/nldev: Fix locking when accessing mr->pd
A race condition in the Linux kernel RDMA subsystem allows unsafe access to memory region protection domains, potentially leading to undefined behavior.
- 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-2026-74334?
CVE-2026-74334 is a high-severity vulnerability in Linux, published on 15 Aug 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:
RDMA/nldev: Fix locking when accessing mr->pd
Sashiko points out that, due to rereg_mr, the PD is actually variable and all the touches in nldev are racy.
Use mr->device instead of mr->pd->device.
Getting the PD restrack ID is more tricky. To avoid disturbing all the happy paths, add an rdma_restrack_sync() operation which is sort of like flush_workqueue() or synchronize_irq(): after it returns, all the old nldev touches to the mr are gone and everything sees the new PD. This makes it safe to reach into the PD pointer.
Which versions are affected by CVE-2026-74334?
How do I fix CVE-2026-74334?
Apply the vendor's patch.
Is CVE-2026-74334 being exploited?
There is no known exploitation of CVE-2026-74334 in the wild and no public exploit code.
Sources
Also known as AZL-96486, BELL-CVE-2026-74334, DEBIAN-CVE-2026-74334, GHSA-g8r2-wj85-rq7q, UBUNTU-CVE-2026-74334.