CVE-2025-40061 RDMA/rxe: Fix race in do_task() when draining
A race condition in the Linux kernel RDMA driver allows a use-after-free, potentially enabling local attackers to execute code or escalate privileges.
- 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-2025-40061?
CVE-2025-40061 is a high-severity vulnerability in Linux, published on 28 Oct 2025. 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/rxe: Fix race in do_task() when draining
When do_task() exhausts its iteration budget (!ret), it sets the state to TASK_STATE_IDLE to reschedule, without a secondary check on the current task->state. This can overwrite the TASK_STATE_DRAINING state set by a concurrent call to rxe_cleanup_task() or rxe_disable_task().
While state changes are protected by a spinlock, both rxe_cleanup_task() and rxe_disable_task() release the lock while waiting for the task to finish draining in the while(!is_done(task)) loop. The race occurs if do_task() hits its iteration limit and acquires the lock in this window. The cleanup logic may then proceed while the task incorrectly reschedules itself, leading to a potential use-after-free.
This bug was introduced during the migration from tasklets to workqueues, where the special handling for the draining case was lost.
Fix this by restoring the original pre-migration behavior. If the state is TASK_STATE_DRAINING when iterations are exhausted, set cont to 1 to force a new loop iteration. This allows the task to finish its work, so that a subsequent iteration can reach the switch statement and correctly transition the state to TASK_STATE_DRAINED, stopping the task as intended.
Which versions are affected by CVE-2025-40061?
How do I fix CVE-2025-40061?
Apply the vendor's patch.
Is CVE-2025-40061 being exploited?
There is no known exploitation of CVE-2025-40061 in the wild and no public exploit code.
Sources
Also known as AZL-68837, BELL-CVE-2025-40061, DEBIAN-CVE-2025-40061, GHSA-c64c-4m7r-82v9, ROOT-OS-DEBIAN-13-CVE-2025-40061, ROOT-OS-UBUNTU-2404-CVE-2025-40061 and 1 more.