[kernel-hardening] Re: [PATCH v2 02/11] mm: Hardened usercopy
From: Kees Cook <hidden>
Date: 2016-07-15 19:14:28
Also in:
linux-arch, linux-mm, linuxppc-dev, lkml, sparclinux
From: Kees Cook <hidden>
Date: 2016-07-15 19:14:28
Also in:
linux-arch, linux-mm, linuxppc-dev, lkml, sparclinux
On Fri, Jul 15, 2016 at 12:00 PM, Daniel Micay [off-list ref] wrote:
quoted
This could be a BUG, but I'd rather not panic the entire kernel.It seems unlikely that it will panic without panic_on_oops and that's an explicit opt-in to taking down the system on kernel logic errors exactly like this. In grsecurity, it calls the kernel exploit handling logic (panic if root, otherwise kill all process of that user and ban them until reboot) but that same logic is also called for BUG via oops handling so there's only really a distinction with panic_on_oops=1. Does it make sense to be less fatal for a fatal assertion that's more likely to be security-related? Maybe you're worried about having some false positives for the whitelisting portion, but I don't think those will lurk around very long with the way this works.
I'd like it to dump stack and be fatal to the process involved, but yeah, I guess BUG() would work. Creating an infrastructure for handling security-related Oopses can be done separately from this (and I'd like to see that added, since it's a nice bit of configurable reactivity to possible attacks). -Kees -- Kees Cook Chrome OS & Brillo Security