CVE-2026-99144
Received Received - Intake

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Vulnerability report for CVE-2026-99144, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-10-28

Last updated on: 2026-10-28

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix use-after-free of a destroyed user DSQ by a deferred reenqueue A deferred reenqueue can read a freed user DSQ. The request stays on its CPU's deferred list until run_deferred() takes it, and the RCU callback that frees the DSQ assumes that the grace period has flushed it, so exit_dsq() checks the per-CPU node without the deferred list lock. A grace period waits for readers in flight, not for a pending run_deferred(). A run_deferred() which starts after the grace period began can detach the request right before the callback looks and then read the freed DSQ's id. Cancel the pending requests before the grace period instead. The irq work that frees the DSQ unlinks every CPU's request under the per-CPU deferred list lock, and schedule_dsq_reenq() ignores a new request under the same lock once the id is invalid. Only a run_deferred() that started before the grace period can hold a request, and it runs with IRQs disabled, so the grace period waits for it and nothing touches the DSQ after the callback.

CVSS Scores

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Meta Information

Published
2026-10-28
Last Modified
2026-10-28
Generated
2026-10-28
AI Q&A
2026-10-28
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 3 associated CPEs
Vendor Product Version / Range
Linux Linux 84b1a0ea0b7c23dec240783a592e480780efe459
Linux Linux 84b1a0ea0b7c23dec240783a592e480780efe459
Linux Linux 7.1

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a use-after-free issue in the sched_ext component. A deferred reenqueue operation can access a user DSQ (Deadline Scheduling Queue) that has already been freed. The problem occurs because the cleanup process assumes all pending operations are flushed, but a delayed reenqueue can still reference the freed DSQ before the cleanup completes.

Impact Analysis

This vulnerability could lead to system instability or crashes if exploited. It may allow an attacker to cause a denial-of-service condition or potentially execute arbitrary code with kernel privileges. Systems running affected versions of the Linux kernel are at risk.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve the use-after-free issue in sched_ext. Monitor kernel logs for crashes or errors related to DSQ handling.

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