Messages in this thread | | | Date | Mon, 3 Oct 2022 21:37:06 -0700 | From | Kees Cook <> | Subject | Re: [PATCH v2 29/39] x86/cet/shstk: Support wrss for userspace |
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On Mon, Oct 03, 2022 at 04:00:36PM -0700, Andy Lutomirski wrote: > On 10/3/22 15:28, Kees Cook wrote: > > On Thu, Sep 29, 2022 at 03:29:26PM -0700, Rick Edgecombe wrote: > > > For the current shadow stack implementation, shadow stacks contents easily > > > be arbitrarily provisioned with data. > > > > I can't parse this sentence. > > > > > This property helps apps protect > > > themselves better, but also restricts any potential apps that may want to > > > do exotic things at the expense of a little security. > > > > Is anything using this right now? Wouldn't thing be safer without WRSS? > > (Why can't we skip this patch?) > > > > So that people don't write programs that need either (shstk off) or (shstk > on and WRSS on) and crash or otherwise fail on kernels that support shstk > but don't support WRSS, perhaps?
Right, yes. I meant more "what programs currently need WRSS to operate under shstk? (And what is it that they are doing that needs it?)"
All is see currently is compiler self-tests and emulators using it? https://codesearch.debian.net/search?q=%5Cb%28wrss%7CWRSS%29%5Cb&literal=0&perpkg=1
-- Kees Cook
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