CVE-2026-81010

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.