CVE-2023-53461 io_uring: wait interruptibly for request completions on exit
A flaw in Linux kernel io_uring exit handling can trigger hung task detection, potentially causing a system crash if panic-on-hung-task is enabled.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-53461?
CVE-2023-53461 is a medium-severity denial of service vulnerability in Linux kernel, published on 1 Oct 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
io_uring: wait interruptibly for request completions on exit
WHen the ring exits, cleanup is done and the final cancelation and waiting on completions is done by io_ring_exit_work. That function is invoked by kworker, which doesn't take any signals. Because of that, it doesn't really matter if we wait for completions in TASK_INTERRUPTIBLE or TASK_UNINTERRUPTIBLE state. However, it does matter to the hung task detection checker!
Normally we expect cancelations and completions to happen rather quickly. Some test cases, however, will exit the ring and park the owning task stopped (eg via SIGSTOP). If the owning task needs to run task_work to complete requests, then io_ring_exit_work won't make any progress until the task is runnable again. Hence io_ring_exit_work can trigger the hung task detection, which is particularly problematic if panic-on-hung-task is enabled.
As the ring exit doesn't take signals to begin with, have it wait interruptibly rather than uninterruptibly. io_uring has a separate stuck-exit warning that triggers independently anyway, so we're not really missing anything by making this switch.
Which versions are affected by CVE-2023-53461?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53461?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-53461 being exploited?
There is no known exploitation of CVE-2023-53461 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53461, DEBIAN-CVE-2023-53461, GHSA-w27r-hww7-6vv2, UBUNTU-CVE-2023-53461.