CVE-2026-92511 RDMA/core: Fix potential use after free in ib_destroy_cq_user()
A use-after-free vulnerability in the Linux kernel RDMA core allows attackers to potentially execute code or escalate privileges via the netlink path.
- 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-2026-92511?
CVE-2026-92511 is a high-severity use after free vulnerability in Linux, published on 17 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:
RDMA/core: Fix potential use after free in ib_destroy_cq_user()
When accessing a CQ via the netlink path the only synchronization mechanism for the said CQ is rdma_restrack_get(). Currently, rdma_restrack_del() is invoked at the end of ib_destroy_cq_user(), which is too late, since by that point vendor-specific resources associated with the CQ might already be freed. This can leave a short window where the CQ remains accessible through restrack, leading to a potential use-after-free.
Fix this by moving the rdma_restrack_begin_del() call to the start of ib_destroy_cq_user(), ensuring that the CQ is removed from restrack before its internal resources are released. This guarantees that no new users hold references to a CQ that is in the process of destruction.
In addition, this change preserves the intended inverted order between create and destroy routines: resources are added to restrack at the end of successful creation, and hence shall be removed from the restrack first thing during the destruction flow, which keeps the lifecycle management consistent and predictable.
Which versions are affected by CVE-2026-92511?
How do I fix CVE-2026-92511?
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-2026-92511 being exploited?
There is no known exploitation of CVE-2026-92511 in the wild and no public exploit code.
Sources
Also known as AZL-102734, BELL-CVE-2026-92511, DEBIAN-CVE-2026-92511, GHSA-rx24-hf7h-rf8w, UBUNTU-CVE-2026-92511.