Re: [PATCH v5 00/15] x86: Add support for Clang CFI

Kees Cook
2021-10-13T19:07:53Z

On Wed, Oct 13, 2021 at 11:16:43AM -0700, Sami Tolvanen wrote:
> This series adds support for Clang's Control-Flow Integrity (CFI)
> checking to x86_64. With CFI, the compiler injects a runtime
> check before each indirect function call to ensure the target is
> a valid function with the correct static type. This restricts
> possible call targets and makes it more difficult for an attacker
> to exploit bugs that allow the modification of stored function
> pointers. For more details, see:
>
> https://clang.llvm.org/docs/ControlFlowIntegrity.html
>
> Note that v5 is based on tip/master. The first two patches contain
> objtool support for CFI, the remaining patches change function
> declarations to use opaque types, fix type mismatch issues that
> confuse the compiler, and disable CFI where it can't be used.

x86 folks: I'd prefer this series went via -tip, but I can carry it for
-next as well. What would you like to do here? I think it's ready.

Thanks!

-Kees

--
Kees Cook