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SubjectRe: [PATCH] randstruct: temporarily disable clang support
On Sat, Feb 4, 2023 at 11:06 AM Kees Cook <keescook@chromium.org> wrote:
>
> On Fri, Feb 03, 2023 at 11:42:01AM -0800, Eric Biggers wrote:
> > From: Eric Biggers <ebiggers@google.com>
> >
> > Randstruct with clang is currently unsafe to use in any clang release
> > that supports it, due to a clang bug that is causing miscompilations:
> > "-frandomize-layout-seed inconsistently randomizes all-function-pointers
> > structs" (https://github.com/llvm/llvm-project/issues/60349). Disable
> > it temporarily until the bug is fixed and the fix is released in a clang
> > version that can be checked for.
> >
> > Fixes: 035f7f87b729 ("randstruct: Enable Clang support")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Eric Biggers <ebiggers@google.com>
> > ---
> > security/Kconfig.hardening | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/security/Kconfig.hardening b/security/Kconfig.hardening
> > index 53baa95cb644..aad16187148c 100644
> > --- a/security/Kconfig.hardening
> > +++ b/security/Kconfig.hardening
> > @@ -280,7 +280,8 @@ config ZERO_CALL_USED_REGS
> > endmenu
> >
> > config CC_HAS_RANDSTRUCT
> > - def_bool $(cc-option,-frandomize-layout-seed-file=/dev/null)
> > + # Temporarily disabled due to https://github.com/llvm/llvm-project/issues/60349
> > + def_bool n
> >
> > choice
> > prompt "Randomize layout of sensitive kernel structures"
> >
> > base-commit: 7b753a909f426f2789d9db6f357c3d59180a9354
> > --
> > 2.39.1
>
> This should be fixed with greater precision -- i.e. this is nearly fixed
> in Clang now, and is likely to be backported. So I think we'll need
> versioned checks here.
>
> --
> Kees Cook
>

Bill has requested cherry-pick the llvm-project fix into the
release/16.x branch [1].
https://github.com/llvm/llvm-project-release-prs/pull/276
It may take one day to land.

[1]: https://github.com/llvm/llvm-project/tree/release/16.x

--
宋方睿

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