Messages in this thread | | | Date | Thu, 15 Oct 2020 12:05:22 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 1/2] x86/insn: Fix some potential undefined behavior. |
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On Wed, Oct 14, 2020 at 11:21:47PM -0700, Ian Rogers wrote: > From: Numfor Mbiziwo-Tiapo <nums@google.com> > > If insn_init is given a NULL kaddr and 0 buflen then validate_next will > perform arithmetic on NULL, add a guard to avoid this.
How is this a problem? NULL is (void *)0, you can do arithmetic on that just fine.
Is UBSAN taking drugs again?
> Don't perform unaligned loads in __get_next and __peek_nbyte_next as > these are forms of undefined behavior.
Fair enough; that could actually be a problem when we start to cross-build this stuff. A RISC hosted version of the x86 decoder could indeed trip this up.
But also, these are two changes in one patch.
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