Provide references for CVE-2021-4440.
Where can I find more information about CVE-2021-4440?
References are available at: https://git.kernel.org/stable/c/1424ab4bb386df9cc590c73afa55f13e9b00dea2, https://grsecurity.net/cve-2021-4440_linux_cna_case_study.