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From:   Jason Andryuk <jandryuk@gmail.com>
Date:   Wed, 11 Oct 2023 09:22:29 -0400
Message-ID: <CAKf6xpu4vQSKFykwygcCtnnJtcQbgVTuaNvAwDLeV8cZAectHg@mail.gmail.com>
Subject: Re: [PATCH][next] xen/xenbus: Add __counted_by for struct read_buffer
 and use struct_size()
To:     "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc:     Juergen Gross <jgross@suse.com>,
        Stefano Stabellini <sstabellini@kernel.org>,
        Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>,
        xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
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On Mon, Oct 9, 2023 at 2:55=E2=80=AFPM Gustavo A. R. Silva
<gustavoars@kernel.org> wrote:
>
> Prepare for the coming implementation by GCC and Clang of the __counted_b=
y
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
> array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
>
> While there, use struct_size() helper, instead of the open-coded
> version, to calculate the size for the allocation of the whole
> flexible structure, including of course, the flexible-array member.
>
> This code was found with the help of Coccinelle, and audited and
> fixed manually.
>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Reviewed-by: Jason Andryuk <jandryuk@gmail.com>