CVE-2026-46181 RDMA/mlx4: Fix mis-use of RCU in mlx4_srq_event()
A race condition in the Linux kernel RDMA mlx4 driver can cause a system crash if an event is delivered before initialization completes.
- 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-2026-46181?
CVE-2026-46181 is a high-severity vulnerability in Linux kernel, published on 28 May 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/mlx4: Fix mis-use of RCU in mlx4_srq_event()
Sashiko points out the radix_tree itself is RCU safe, but nothing ever frees the mlx4_srq struct with RCU, and it isn't even accessed within the RCU critical section. It also will crash if an event is delivered before the srq object is finished initializing.
Use the spinlock since it isn't easy to make RCU work, use refcount_inc_not_zero() to protect against partially initialized objects, and order the refcount_set() to be after the srq is fully initialized.
Weakness: CWE-366
Which versions are affected by CVE-2026-46181?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46181?
Apply the vendor's patch.
Is CVE-2026-46181 being exploited?
There is no known exploitation of CVE-2026-46181 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88964, BELL-CVE-2026-46181, DEBIAN-CVE-2026-46181, GHSA-pw2f-xmgc-f22m, ROOT-OS-DEBIAN-11-CVE-2026-46181, ROOT-OS-DEBIAN-12-CVE-2026-46181 and 4 more.