Linux kernel preemption disable bug wedges system (scx_claim_exit)
CVE-2026-43482 Published on May 13, 2026
sched_ext: Disable preemption between scx_claim_exit() and kicking helper work
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.
Products Associated with CVE-2026-43482
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Affected Versions
Linux:- Version f0e1a0643a59bf1f922fa209cec86a170b784f3f and below 41423912f7ac7494ccd6eef411227b4efce740e0 is affected.
- Version f0e1a0643a59bf1f922fa209cec86a170b784f3f and below 522acaae34aa7e05859260056b39c7c030592a0c is affected.
- Version f0e1a0643a59bf1f922fa209cec86a170b784f3f and below 5131dbec2c10961b34f844bc30b400c3fa0bcc72 is affected.
- Version f0e1a0643a59bf1f922fa209cec86a170b784f3f and below 83236b2e43dba00bee5b82eb5758816b1a674f6a is affected.
- Version 6.12 is affected.
- Before 6.12 is unaffected.
- Version 6.12.78, <= 6.12.* is unaffected.
- Version 6.18.20, <= 6.18.* is unaffected.
- Version 6.19.9, <= 6.19.* is unaffected.
- Version 7.0, <= * is unaffected.