The vgacon subsystem in the Linux kernel before 5.8.10 mishandles software scrollback. There is a vgacon_scrolldelta out-of-bounds read, aka CID-973c096f6a85.
https://security.netapp.com/advisory/ntap-20210805-0001/
https://seclists.org/oss-sec/2020/q3/176
https://github.com/torvalds/linux/commit/973c096f6a85e5b5f2a295126ba6928d9a6afd45
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.8.10