In the Linux kernel before 5.17.3, fs/io_uring.c has a use-after-free due to a race condition in io_uring timeouts. This can be triggered by a local user who has no access to any user namespace; however, the race condition perhaps can only be exploited infrequently.
https://www.openwall.com/lists/oss-security/2022/04/22/3
https://www.debian.org/security/2022/dsa-5127
https://ruia-ruia.github.io/2022/08/05/CVE-2022-29582-io-uring/
https://github.com/torvalds/linux/commit/e677edbcabee849bfdd43f1602bccbecf736a646
https://github.com/Ruia-ruia/CVE-2022-29582-Exploit
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.17.3
http://www.openwall.com/lists/oss-security/2024/04/24/3