Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34;
Message-ID: <933c901f-ff4f-2769-6277-b63b96903034@embeddedor.com>
Date:   Sun, 1 Oct 2023 08:51:32 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.15.1
Subject: Re: [PATCH][next] ALSA: 6fire: Fix undefined behavior bug in struct
 comm_runtime
Content-Language: en-US
To:     Kees Cook <keescook@chromium.org>,
        "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc:     Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
        Jussi Kivilinna <jussi.kivilinna@iki.fi>,
        alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
References: <ZRb0WiViajjqcyKT@work> <202309291024.14F6DA0@keescook>
From:   "Gustavo A. R. Silva" <gustavo@embeddedor.com>
In-Reply-To: <202309291024.14F6DA0@keescook>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 9/29/23 19:26, Kees Cook wrote:
> On Fri, Sep 29, 2023 at 05:59:22PM +0200, Gustavo A. R. Silva wrote:
>> `struct urb` is a flexible structure, which means that it contains a
>> flexible-array member at the bottom. This could potentially lead to an
>> overwrite of the objects following `receiver` in `struct comm_runtime`,
>> among them some function pointers.
>>
>> Fix this by placing the declaration of object `receiver` at the end of
>> `struct comm_runtime`.
>>
>> Fixes: ddb6b5a96437 ("ALSA: 6fire: fix DMA issues with URB transfer_buffer usage")
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> 
> Should these mention -Wflex-array-member-not-at-end ?

Probably, yes. I wasn't sure about mentioning it because it's not been released yet.

> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> 

Thanks!
--
Gustavo