Re: [PATCH v1 2/2] kexec: Introduce kexec_reboot_disabled

From: Steven Rostedt
Date: Tue Nov 29 2022 - 09:33:00 EST


On Tue, 29 Nov 2022 14:44:50 +0100
Philipp Rudo <prudo@xxxxxxxxxx> wrote:

> An alternative approach and sort of compromise I see is to convert
> kexec_load_disabled from a simple on/off switch to a counter on how
> often a kexec load can be made (in practice a tristate on/off/one-shot
> should be sufficient). Ideally the reboot and panic path will
> have separate counters. With that you could for example use
> kexec_load_limit.reboot=0 and kexec_load_limit.panic=1 to disable the
> load of images for reboot while still allow to load a crash kernel
> once. With this you have the flexibility you need while also preventing
> a race where an attacker overwrites your crash kernel before you can
> toggle the switch. What do you think?

I actually like this idea :-)

-- Steve