CVE Catalog

CVE-2026-90432

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the sched_ext scheduler's scx_hardlockup() deferred the abort via irq_work, which does not work in NMI context and prevented recovery from self-detected hardlockups. It also returned true even when the abort was refused, suppressing the kernel's hardlockup report.

Risk Assessment

This can cause a permanent CPU hardlockup without automatic recovery and hide hardlockup reports, hindering diagnostics.

Recommendation

Update the Linux kernel to a version where scx_hardlockup() calls handle_lockup() directly and returns true only when the abort was initiated.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Abort directly from the hardlockup handler scx_hardlockup() defers the abort to an irq_work because exit claiming used to take scx_sched_lock and couldn't run from NMI. The deferral is now unnecessary - claiming is NMI-safe and asserting ->aborting is exactly what breaks the live-locks that hard-lock CPUs. Call handle_lockup() directly and drop the irq_work. This also makes the self-detected case recoverable: the perf watchdog fires on the hard-locked CPU itself, where a queued irq_work never runs with IRQs off. Also fix the return value: %true used to be returned whenever sched_ext was loaded, suppressing the kernel's hardlockup report even when the abort was refused. Return %true only when this call initiated the abort.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS