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 originati…

Overview

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.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Vendor advisories

• Red Hat VEX · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · vex