CVE-2026-43482 sched_ext: Disable preemption between scx_claim_exit() and kicking helper work
A race condition in the Linux kernel scheduler can cause a system wedge if preemption occurs during error handling, leading to denial of service.
- 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-2026-43482?
CVE-2026-43482 is a medium-severity vulnerability in Linux kernel, published on 13 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:
sched_ext: Disable preemption between scx_claim_exit() and kicking helper work
scx_claim_exit() atomically sets exit_kind, which prevents scx_error() from triggering further error handling. After claiming exit, the caller must kick the helper kthread work which initiates bypass mode and teardown.
If the calling task gets preempted between claiming exit and kicking the helper work, and the BPF scheduler fails to schedule it back (since error handling is now disabled), the helper work is never queued, bypass mode never activates, tasks stop being dispatched, and the system wedges.
Disable preemption across scx_claim_exit() and the subsequent work kicking in all callers - scx_disable() and scx_vexit(). Add lockdep_assert_preemption_disabled() to scx_claim_exit() to enforce the requirement.
Which versions are affected by CVE-2026-43482?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-43482?
Apply the vendor's patch.
Is CVE-2026-43482 being exploited?
There is no known exploitation of CVE-2026-43482 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-43482, DEBIAN-CVE-2026-43482, GHSA-rgq2-6gcj-qprf, UBUNTU-CVE-2026-43482.