CVE-2026-46176 RDMA/mlx5: Fix error path fall-through in mlx5_ib_dev_res_srq_init()
A use-after-free vulnerability in the Linux kernel RDMA driver allows attackers to cause denial of service or potentially execute code via crafted network traffic.
- 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-2026-46176?
CVE-2026-46176 is a high-severity use after free 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/mlx5: Fix error path fall-through in mlx5_ib_dev_res_srq_init()
mlx5_ib_dev_res_srq_init() allocates two SRQs, s0 and s1. When ib_create_srq() fails for s1, the error branch destroys s0 but falls through and unconditionally assigns the freed s0 and the ERR_PTR s1 to devr->s0 and devr->s1.
This leads to several problems: the lock-free fast path checks "if (devr->s1) return 0;" and treats the ERR_PTR as already initialised; users in mlx5_ib_create_qp() dereference the freed SRQ or ERR_PTR via to_msrq(devr->s0)->msrq.srqn; and mlx5_ib_dev_res_cleanup() dereferences the ERR_PTR and double-frees s0 on teardown.
Fix by adding the same `goto unlock` in the s1 failure path.
Weakness: CWE-825
Which versions are affected by CVE-2026-46176?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46176?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-46176 being exploited?
There is no known exploitation of CVE-2026-46176 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88836, BELL-CVE-2026-46176, DEBIAN-CVE-2026-46176, GHSA-r8g9-gm9p-ff4h, ROOT-OS-UBUNTU-2404-CVE-2026-46176, UBUNTU-CVE-2026-46176.