linux-kernel - Re: [PATCH] kcov: don't instrument with UBSAN

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 linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20201210084950.208c89ba@canb.auug.org.au>
Date:   Thu, 10 Dec 2020 08:49:50 +1100
From:   Stephen Rothwell <sfr@...b.auug.org.au>
To:     Kees Cook <keescook@...omium.org>
Cc:     Dmitry Vyukov <dvyukov@...gle.com>, akpm@...ux-foundation.org,
        andreyknvl@...gle.com, kasan-dev@...glegroups.com,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Marco Elver <elver@...gle.com>
Subject: Re: [PATCH] kcov: don't instrument with UBSAN

Hi all,

On Wed, 9 Dec 2020 10:54:39 -0800 Kees Cook <keescook@...omium.org> wrote:
>
> On Wed, Dec 09, 2020 at 11:01:52AM +0100, Dmitry Vyukov wrote:
> > Both KCOV and UBSAN use compiler instrumentation. If UBSAN detects a bug
> > in KCOV, it may cause infinite recursion via printk and other common
> > functions. We already don't instrument KCOV with KASAN/KCSAN for this
> > reason, don't instrument it with UBSAN as well.
> > 
> > As a side effect this also resolves the following gcc warning:
> > 
> > conflicting types for built-in function '__sanitizer_cov_trace_switch';
> > expected 'void(long unsigned int,  void *)' [-Wbuiltin-declaration-mismatch]
> > 
> > It's only reported when kcov.c is compiled with any of the sanitizers
> > enabled. Size of the arguments is correct, it's just that gcc uses 'long'
> > on 64-bit arches and 'long long' on 32-bit arches, while kernel type is
> > always 'long long'.
> > 
> > Reported-by: Stephen Rothwell <sfr@...b.auug.org.au>
> > Suggested-by: Marco Elver <elver@...gle.com>
> > Signed-off-by: Dmitry Vyukov <dvyukov@...gle.com>  
> 
> Reviewed-by: Kees Cook <keescook@...omium.org>
> 
> Thanks for chasing this down!
> 
> Andrew, can you add this to the stack of ubsan patches you're carrying,
> please?

Added to linux-next today.

-- 
Cheers,
Stephen Rothwell

Content of type "application/pgp-signature" skipped