CVE-2026-90432

sched_ext: Abort directly from the hardlockup handler

Published Sep 17, 2026 CVSS n/a EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Weaknesses CWE-398
CWE-753
Type Values Removed Values Added
Description 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.
Title sched_ext: Abort directly from the hardlockup handler
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 19, 2026, 9:03 AM
Reserved
Sep 11, 2026, 7:38 PM
Status
Received
Published
Sep 17, 2026, 5:17 PM
Modified
Oct 19, 2026, 9:19 AM