CVE-2026-90432
sched_ext: Abort directly from the hardlockup handler
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.
INFO
Published Date :
Sept. 17, 2026, 5:17 p.m.
Last Modified :
Sept. 17, 2026, 5:17 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the latest version.
- Apply vendor-specific patches for sched_ext.
- Reboot the system after applying updates.
- Verify the hardlockup handler behavior.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-90432.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/3c4b38064937a761ebbf85b1649e812db85eb59e | |
| https://git.kernel.org/stable/c/4d6270bbb4e083a4d2d39f3c36f30f5c939c06ed |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-90432 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-90432
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-90432 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-90432 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 17, 2026
Action Type Old Value New Value 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/90xxx/CVE-2026-90432.json">CVE-2026-90432</a> Added Reference https://git.kernel.org/stable/c/3c4b38064937a761ebbf85b1649e812db85eb59e Added Reference https://git.kernel.org/stable/c/4d6270bbb4e083a4d2d39f3c36f30f5c939c06ed