A flaw use-after-free in function sco_sock_sendmsg() of the Linux kernel HCI subsystem was found in the way user calls ioct UFFDIO_REGISTER or other way triggers race condition of the call sco_conn_del() together with the call sco_sock_sendmsg() with the expected controllable faulting memory page. A privileged local user could use this flaw to crash the system or escalate their privileges on the system.
https://bugzilla.redhat.com/show_bug.cgi?id=1980646
https://github.com/torvalds/linux/commit/99c23da0eed4fd20cae8243f2b51e10e66aa0951
https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html
https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html
https://security.netapp.com/advisory/ntap-20220419-0003/
https://ubuntu.com/security/CVE-2021-3640