A flaw was found in the io-workqueue implementation in the Linux kernel versions prior to 5.15-rc1. The kernel can panic when an improper cancellation operation triggers the submission of new io-uring operations during a shortage of free space. This flaw allows a local user with permissions to execute io-uring requests to possibly crash the system.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-4023
• https://bugzilla.redhat.com/show_bug.cgi?id=2026484