CVE-2023-53461

A flaw was identified in the Linux kernel’s io_uring subsystem related to how request completions are handled when an io_uring instance exits. During cleanup, the function io_ring_exit_work was waiting in an uninterruptible state for request completions. Under certain test and signal conditions (e.g., when the owning task is parked via SIGSTOP), this could block making progress on completions and trigger the kernel’s hung task detection mechanism, potentially leading to system instability or panic on systems configured with panic_on_hung_task.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To prevent a system panic, administrators can disable the panic_on_hung_task kernel parameter. This can be achieved by creating a new sysctl configuration file (e.g., /etc/sysctl.d/99-disable-hung-task-panic.conf) with the content kernel.panic_on_hung_task = 0. Apply the change using sysctl -p /etc/sysctl.d/99-disable-hung-task-panic.conf. This mitigation prevents system panics but does not prevent the hung task condition itself, which may still lead to system instability. A system reboot is required for the change to take full effect.