CVE-2026-64425

Technical Description

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

io_uring/io-wq: re-check IO_WQ_BIT_EXIT for each linked work item

commit 10dc95939817 ("io_uring/io-wq: check IO_WQ_BIT_EXIT inside work

run loop") fixed the obvious case where io_worker_handle_work() took one

exit-bit snapshot before draining pending work, but the fix stops one

level too early.

io_worker_handle_work() now re-checks IO_WQ_BIT_EXIT in its outer work

run loop, yet it still snapshots that bit once before processing a whole

dependent linked-work chain. If io_wq_exit_start() sets IO_WQ_BIT_EXIT

after the first linked item has started, the remaining linked items can

still reuse stale do_kill = false, skip IO_WQ_WORK_CANCEL, and continue

running after exit has begun.

Move the check further inside, so it covers linked items too. Note: this

is a syzbot special as it loves setting up tons of slow linked work on

weird devices like msr that take forever to read, and immediately close

the ring. Exit then takes

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

References