When setting font with malicous data by ioctl cmd PIO_FONT,kernel will write memory out of bounds.
https://www.openeuler.org/en/security/cve/detail.html?id=CVE-2021-33656&packageName=kernel
http://www.openwall.com/lists/oss-security/2022/07/19/3
https://lists.debian.org/debian-lts-announce/2022/10/msg00000.html