Re: [PATCH] Restrict access to TIOCLINUX
Hanno Böck <[email protected]>
| Newsgroups | com.openwall.lists.kernel-hardening |
|---|---|
| Message-ID | <[email protected]> |
On Sun, 2 Apr 2023 19:23:44 +0200 Greg KH <[email protected]> wrote: > > Do you have other proposals how to fix this issue? One could > > introduce an option like for TIOCSTI that allows disabling > > selection features by default. > > What exact issue are you trying to fix here? The fact that the selection features of TIOCLINUX can be used for privilege escalation. I already mentioned this in the original patch description, but I think the minitty.c example here illustrates this well: https://www.openwall.com/lists/oss-security/2023/03/14/3 Compile it, do sudo -u [anynonprivilegeduser] ./minitty It'll execute shell code with root permission. -- Hanno Böck https://hboeck.de/