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Date:   Tue, 29 Jun 2021 16:25:54 +0200
From:   Heiko Carstens <hca@linux.ibm.com>
To:     Kees Cook <keescook@chromium.org>
Cc:     Julian Wiedmann <jwi@linux.ibm.com>,
        Karsten Graul <kgraul@linux.ibm.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>, linux-kernel@vger.kernel.org,
        linux-s390@vger.kernel.org, linux-hardening@vger.kernel.org
Subject: Re: [PATCH] s390: iucv: Avoid field over-reading memcpy()
Message-ID: <YNstcvvzHKnrvW3d@osiris>
References: <20210616201942.1246211-1-keescook@chromium.org>
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On Wed, Jun 16, 2021 at 01:19:42PM -0700, Kees Cook wrote:
> In preparation for FORTIFY_SOURCE performing compile-time and run-time
> field bounds checking for memcpy(), memmove(), and memset(), avoid
> intentionally reading across neighboring array fields.
> 
> Add a wrapping struct to serve as the memcpy() source so the compiler
> can perform appropriate bounds checking, avoiding this future warning:
> 
> In function '__fortify_memcpy',
>     inlined from 'iucv_message_pending' at net/iucv/iucv.c:1663:4:
> ./include/linux/fortify-string.h:246:4: error: call to '__read_overflow2_field' declared with attribute error: detected read beyond size of field (2nd parameter)
> 
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  net/iucv/iucv.c | 22 ++++++++++++----------
>  1 file changed, 12 insertions(+), 10 deletions(-)

This one is for Julian Wiedmann and Karsten Graul.