A vulnerability was found in the Linux Kernel where the function sunkbd_reinit having been scheduled by sunkbd_interrupt before sunkbd being freed. Though the dangling pointer is set to NULL in sunkbd_disconnect, there is still an alias in sunkbd_reinit causing Use After Free.
https://www.openwall.com/lists/oss-security/2020/11/20/5%2C
https://www.openwall.com/lists/oss-security/2020/11/05/2%2C
https://security.netapp.com/advisory/ntap-20210702-0006/
https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html
https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html
https://github.com/torvalds/linux/commit/77e70d351db7de07a46ac49b87a6c3c7a60fca7e