lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 26 Oct 2022 11:26:27 -0700 From: Nick Desaulniers <ndesaulniers@...gle.com> To: Kees Cook <keescook@...omium.org> Cc: linux-hardening@...r.kernel.org, Linus Torvalds <torvalds@...ux-foundation.org>, linux-kernel@...r.kernel.org Subject: Re: [PATCH] fortify: Do not cast to "unsigned char" On Tue, Oct 25, 2022 at 4:17 PM Kees Cook <keescook@...omium.org> wrote: > > Do not cast to "unsigned char", as this needlessly creates type problems > when attempting builds without -Wno-pointer-sign[1]. The intent of the > cast is to drop possible "const" types. > > [1] https://lore.kernel.org/lkml/CAHk-=wgz3Uba8w7kdXhsqR1qvfemYL+OFQdefJnkeqXG8qZ_pA@mail.gmail.com/ > > Suggested-by: Linus Torvalds <torvalds@...ux-foundation.org> > Fixes: 3009f891bb9f ("fortify: Allow strlen() and strnlen() to pass compile-time known lengths") > Cc: Nick Desaulniers <ndesaulniers@...gle.com> > Cc: linux-hardening@...r.kernel.org > Signed-off-by: Kees Cook <keescook@...omium.org> > --- > include/linux/fortify-string.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/fortify-string.h b/include/linux/fortify-string.h > index f3dd5d1a6a25..09a032f6ce6b 100644 > --- a/include/linux/fortify-string.h > +++ b/include/linux/fortify-string.h > @@ -18,7 +18,7 @@ void __write_overflow_field(size_t avail, size_t wanted) __compiletime_warning(" > > #define __compiletime_strlen(p) \ > ({ \ > - unsigned char *__p = (unsigned char *)(p); \ > + char *__p = (char *)(p); \ If the intent of __p is to avoid repeated application of side effects from the evaluation of the macro parameter p, this could also be: __auto_type __p = (p); I think this is nice because it doesn't strip potential const qualifiers from the macro parameter. > size_t __ret = SIZE_MAX; \ > size_t __p_size = __member_size(p); \ > if (__p_size != SIZE_MAX && \ > -- > 2.34.1 > -- Thanks, ~Nick Desaulniers
Powered by blists - more mailing lists