CVE-2026-98217 IB/mlx4: Fix use-after-free on pkey sysfs registration failure
A use-after-free in the Linux kernel mlx4 InfiniBand driver allows local attackers to cause a system crash or potentially execute code via device cleanup.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98217?
CVE-2026-98217 is an use after free vulnerability in Linux, published on 6 Oct 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/mlx4: Fix use-after-free on pkey sysfs registration failure
register_pkey_tree() ignores errors from register_one_pkey_tree() and continues registering the remaining slaves. The per-slave error path has already released the pkey parent kobjects, but their pointers remain stored in the device. A later device cleanup therefore passes the stale pointers to kobject_put(), causing a use-after-free.
Clear the parent pointers after releasing a failed slave tree and skip unregistered trees during device cleanup. This preserves the existing best-effort registration behavior while preventing a second cleanup of the failed tree.
Which versions are affected by CVE-2026-98217?
How do I fix CVE-2026-98217?
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-2026-98217 being exploited?
There is no known exploitation of CVE-2026-98217 in the wild and no public exploit code.
Sources
Also known as AZL-106071, BELL-CVE-2026-98217, DEBIAN-CVE-2026-98217, GHSA-pc9g-8wgv-jv4j, UBUNTU-CVE-2026-98217.