Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Message-ID: <057ee7f7-ce60-45e9-9602-8046f78d8fb9@quicinc.com>
Date:   Thu, 17 Aug 2023 15:03:43 -0700
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH 6/7] wifi: cfg80211: Annotate struct cfg80211_scan_request
 with __counted_by
Content-Language: en-US
To:     Kees Cook <keescook@chromium.org>,
        Johannes Berg <johannes@sipsolutions.net>
CC:     "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        <linux-wireless@vger.kernel.org>, <netdev@vger.kernel.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, <linux-kernel@vger.kernel.org>,
        <llvm@lists.linux.dev>, <linux-hardening@vger.kernel.org>
References: <20230817211114.never.208-kees@kernel.org>
 <20230817211531.4193219-6-keescook@chromium.org>
From:   Jeff Johnson <quic_jjohnson@quicinc.com>
In-Reply-To: <20230817211531.4193219-6-keescook@chromium.org>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 8/17/2023 2:15 PM, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
> 
> As found with Coccinelle[1], add __counted_by for struct cfg80211_scan_request.
> Additionally, since the element count member must be set before accessing
> the annotated flexible array member, move its initialization earlier.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Johannes Berg <johannes@sipsolutions.net>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: Jakub Kicinski <kuba@kernel.org>
> Cc: Paolo Abeni <pabeni@redhat.com>
> Cc: linux-wireless@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Jeff Johnson <quic_jjohnson@quicinc.com>