Messages in this thread | | | Date | Tue, 18 Oct 2022 22:05:03 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH] x86/ibt: Implement FineIBT |
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On Tue, Oct 18, 2022 at 11:09:13AM -0700, Kees Cook wrote: > I still think it's worth noting it does technically weaken the > "attacker-controlled executable memory content injection" attack > requirements, too. While an attacker needs to make sure they place an > ENDBR at the start of their injected code, they no longer need to also > learn and inject the CFI hash too, as the malicious code can just not > do the check at all. The difference in protection currently isn't much.
Hmm, true; although I do feel that the moment attackers can write code we might be having worse problems.
> It's not a very difficult requirement to get attacker-controlled bytes > into executable memory, as there are already existing APIs that provide > this to varying degrees of reachability, utility, and discoverability -- > for example, BPF JIT when constant blinding isn't enabled (the unfortunate > default).
BPF has another problem in that the current control transfer to BPF progs is nocfi. At the very least we can have them have a hash, no?
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