Re: TTY pushback vulnerabilities / TIOCSTI

[Jakub Wilk <jwilk () jwilk net>]

* Hanno Böck <hanno () hboeck de>, 2023-03-14 09:51:
> In the 2017 post solar designer mentioned that the Linux kernel 
> developers have multiple times rejected changes in the kernel.

I believe this is the post in question:
https://www.openwall.com/lists/oss-security/2017/06/03/9

> Starting with Kernel 6.2 it is possible to disable TIOCSTI (unset 
> CONFIG_LEGACY_TIOCSTI).

Nice, but...

On Linux virtual terminals, it's possible to achieve pretty much the 
same effect using TIOCLINUX, the ioctl used by gpm to implement 
copy&pasting.

I've attached a minimal PoC. A more elaborate one is here:
https://github.com/jwilk/ttyjack

--
Jakub Wilk

Attachment: minittyjack.c
Description: