Use of a Non-reentrant Function in a Concurrent Context Affecting kernel6.18-debuginfo package, versions <1:6.18.54-121.166.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.18% (7th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNEL618DEBUGINFO-21423710
  • published22 Oct 2026
  • disclosed11 Sept 2026

Introduced: 11 Sep 2026

CVE-2026-81010  (opens in a new tab)
CWE-663  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel6.18-debuginfo to version 1:6.18.54-121.166.amzn2023 or higher.
This issue was patched in ALAS2023-2026-3192.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel6.18-debuginfo package and not the kernel6.18-debuginfo package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

io_uring/waitid: honor task_work cancellation

io_waitid_cb() may run through the fallback task_work path when task_work_add() can no longer queue work to the originating task. The fallback runs from a kworker and io_uring marks such task work as canceled through tw.cancel.

io_waitid_cb() currently ignores tw.cancel and calls __do_wait(). waitid is task-context dependent: __do_wait() performs child lookup relative to current, and the retry path also uses current->signal->wait_chldexit. If the callback runs from the fallback kworker, current is therefore not the task that submitted the request.

Honor tw.cancel before entering __do_wait(). Complete the request with -ECANCELED and skip the siginfo copy, since canceled task work may run without the submitting task's userspace execution context.

Keep the existing siginfo handling for normal waitid completion and explicit cancellation.

CVSS Base Scores

version 3.1