The rbd block device driver in drivers/block/rbd.c in the Linux kernel through 5.8.9 used incomplete permission checking for access to rbd devices, which could be leveraged by local attackers to map or unmap rbd block devices, aka CID-f44d04e696fe.
https://twitter.com/grsecurity/status/1304537507560919041
https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html
https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html
https://lists.debian.org/debian-lts-announce/2020/09/msg00025.html
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00021.html
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00001.html