From patchwork Thu Aug 8 22:11:15 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 13758235 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A361555769; Thu, 8 Aug 2024 22:11:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723155078; cv=none; b=JrgVehyXAGC3sQqUSbxIoarwwTmRlHScM+KFaTifj3Npb4tO6E2/iK3T2EFJuiMpqjac4oYuseRcs0Tw7zkJID0hHdqAaPRJbzt2sgBEEpVHnWh0kNGdfn35X2551C9nKUWgcwKhJI9P2B4znJ81VJDjSUHoWmWfWkrI3YHpN0A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723155078; c=relaxed/simple; bh=e/zB+LA0zHnznYATwpefdryXkaCV34ukyDo/MVUOmQw=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=AawJchib25CBUWblze6uX0K0Tk5r57CvuVY1HSHdfIj4PnV0nVFfiZWyX0b0QXoWliiEh5e3BMd2X0HOBirMDc0M+y53S6v9+9xSYGppu0mVVwsw5v7lFIyqNOR8PmVED9Eg9D5AtBf7FPeQQXv3vPty0AN2aLIDqGT09Xy/2Jc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hX4NJJW1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hX4NJJW1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BDA8DC4AF0C; Thu, 8 Aug 2024 22:11:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1723155078; bh=e/zB+LA0zHnznYATwpefdryXkaCV34ukyDo/MVUOmQw=; h=Date:From:To:Cc:Subject:From; b=hX4NJJW1aRWhgoINveO9UKbxkL3kdDnaBXF1X8cxVAnBsW+CdrojX0ciMUjV0qRhS 6z+Hi1iDIXwBP3dn95oFfGK3tgchLZ+mOmiTkI8/1luHpWvh/tSwQFy6Z734Ea3hCe iD4oJ6ksCoTArsuwa7jIGLLvZuv8qw48b979cJNk1nSPE5YsQPwP7zKZl5IsQs/rss 1KOxwj9wAeYjwsmnx801l7NtmucULMwsP4xTGImbhZUmdrFp2IqAGHO9GqrTxh+P9Z BmR+XouxkwxEFc+VPinoL7o2gXZwntfGbrj/4t+BTfITtMKDYUwig1qb2i8GQj+vjD fY7LbFQF3+sIg== Date: Thu, 8 Aug 2024 16:11:15 -0600 From: "Gustavo A. R. Silva" To: Kalle Valo Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] wifi: mwl8k: Use static_assert() to check struct sizes Message-ID: Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Commit 5c4250092fad ("wifi: mwl8k: Avoid -Wflex-array-member-not-at-end warnings") introduced tagged `struct mwl8k_cmd_pkt_hdr`. We want to ensure that when new members need to be added to the flexible structure, they are always included within this tagged struct. We use `static_assert()` to ensure that the memory layout for both the flexible structure and the tagged struct is the same after any changes. Signed-off-by: Gustavo A. R. Silva --- drivers/net/wireless/marvell/mwl8k.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/wireless/marvell/mwl8k.c b/drivers/net/wireless/marvell/mwl8k.c index b130e057370f..bab9ef37a1ab 100644 --- a/drivers/net/wireless/marvell/mwl8k.c +++ b/drivers/net/wireless/marvell/mwl8k.c @@ -587,6 +587,7 @@ static int mwl8k_request_firmware(struct mwl8k_priv *priv, char *fw_image, } struct mwl8k_cmd_pkt { + /* New members MUST be added within the __struct_group() macro below. */ __struct_group(mwl8k_cmd_pkt_hdr, hdr, __packed, __le16 code; __le16 length; @@ -596,6 +597,8 @@ struct mwl8k_cmd_pkt { ); char payload[]; } __packed; +static_assert(offsetof(struct mwl8k_cmd_pkt, payload) == sizeof(struct mwl8k_cmd_pkt_hdr), + "struct member likely outside of __struct_group()"); /* * Firmware loading.