From patchwork Mon Apr 7 23:28:20 2025 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: 14041991 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 95B4E1C3BE2; Mon, 7 Apr 2025 23:28:23 +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=1744068503; cv=none; b=Z9gClrOqr/FU6TgNMxrx02Rvn/hGea77diNTVj9N3i64tzCHSHq1NT3km2pA1WGSWNIz8Z6SzDbEjq9VWrig6aey0XvYJXvc/G+dIb7dDPsM11oOf54ic6xSs0gUun4PmjZuCfliKvYNb3u7ZEMaQ05OgDJulcs2S0f9sDKK0i0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744068503; c=relaxed/simple; bh=CVByR+4DUcPMIUDLKFFCym0RNlJROf+tgLBlalzq684=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=CKwNyDLgBkRm42hc11DV3JClmGdmEmPfbOJdTLAwsjVi1Tqb/eupkvqNT+pn2ta1TqI41HrY6aaSHcNnWjeVbdzJ4322x80cjM6dTROhjvgCc/92i9SS5b/EK366I8Mhp97NIoWPIoQUF17HBsvRuFHaJ5jkNSMMsO6R2hwC7eI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Dc/+YKaC; 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="Dc/+YKaC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 807C3C4CEDD; Mon, 7 Apr 2025 23:28:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744068503; bh=CVByR+4DUcPMIUDLKFFCym0RNlJROf+tgLBlalzq684=; h=Date:From:To:Cc:Subject:From; b=Dc/+YKaCZAPvYGK1OpQkKOxUDC4ZO/1otb1fw/TRkoT1ODBzj3oSSQds4z2ycU937 NLnNR77OWPHc2oP4nPrniVwMT2cAvw6tR8+zW170fZaOtJJPUro7I/wiMi/U0BdSwj b/D7rl3VK3Ra8uk/x5q8es0WnvYaixS109NKHmjTcZHWUfRAISgW8sXXDFn6ax5PV0 yzPyiu02cfktINIdyhMlZGl+bMLO+o3irAziOdQk3+UgrGJJPRLcSY6onqa2kfqSZA yRswvfcRXKdC4HKzNujhe6fReAOvHs5dfrftn4xCFS69NvOLKMw729826evop/5AKh cJzRYWcTDvRqw== Date: Mon, 7 Apr 2025 17:28:20 -0600 From: "Gustavo A. R. Silva" To: Krzysztof Kozlowski , Kees Cook Cc: linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH v3][next] w1: Avoid -Wflex-array-member-not-at-end warnings 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 -Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally. Use the `DEFINE_RAW_FLEX()` helper for on-stack definitions of a flexible structure where the size of the flexible-array member is known at compile-time, and refactor the rest of the code, accordingly. So, with these changes, fix the following warnings: drivers/w1/w1_netlink.c:198:31: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] drivers/w1/w1_netlink.c:219:31: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] Reviewed-by: Kees Cook Signed-off-by: Gustavo A. R. Silva --- Changes in v3: - Use direct object assignments instead of memcpy(), and gain type checking. (Kees) - Add RB tag. Changes in v2: - Fix memcpy() instance - use new pointer `pkg_msg`, instead of `packet`. (Kees) - Link: https://lore.kernel.org/linux-hardening/Z_QpOlDTvyfRs4Su@kspp/ v1: - Link: https://lore.kernel.org/linux-hardening/Z-WD2NP_1A0ratnI@kspp/ drivers/w1/w1_netlink.c | 42 ++++++++++++++++++++--------------------- 1 file changed, 20 insertions(+), 22 deletions(-) diff --git a/drivers/w1/w1_netlink.c b/drivers/w1/w1_netlink.c index 691978cddab7..e6b59d921076 100644 --- a/drivers/w1/w1_netlink.c +++ b/drivers/w1/w1_netlink.c @@ -194,16 +194,16 @@ static void w1_netlink_queue_status(struct w1_cb_block *block, static void w1_netlink_send_error(struct cn_msg *cn, struct w1_netlink_msg *msg, int portid, int error) { - struct { - struct cn_msg cn; - struct w1_netlink_msg msg; - } packet; - memcpy(&packet.cn, cn, sizeof(packet.cn)); - memcpy(&packet.msg, msg, sizeof(packet.msg)); - packet.cn.len = sizeof(packet.msg); - packet.msg.len = 0; - packet.msg.status = (u8)-error; - cn_netlink_send(&packet.cn, portid, 0, GFP_KERNEL); + DEFINE_RAW_FLEX(struct cn_msg, packet, data, + sizeof(struct w1_netlink_msg)); + struct w1_netlink_msg *pkt_msg = (struct w1_netlink_msg *)packet->data; + + *packet = *cn; + *pkt_msg = *msg; + packet->len = sizeof(*pkt_msg); + pkt_msg->len = 0; + pkt_msg->status = (u8)-error; + cn_netlink_send(packet, portid, 0, GFP_KERNEL); } /** @@ -215,22 +215,20 @@ static void w1_netlink_send_error(struct cn_msg *cn, struct w1_netlink_msg *msg, */ void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg) { - struct { - struct cn_msg cn; - struct w1_netlink_msg msg; - } packet; - memset(&packet, 0, sizeof(packet)); + DEFINE_RAW_FLEX(struct cn_msg, packet, data, + sizeof(struct w1_netlink_msg)); + struct w1_netlink_msg *pkt_msg = (struct w1_netlink_msg *)packet->data; - packet.cn.id.idx = CN_W1_IDX; - packet.cn.id.val = CN_W1_VAL; + packet->id.idx = CN_W1_IDX; + packet->id.val = CN_W1_VAL; - packet.cn.seq = dev->seq++; - packet.cn.len = sizeof(*msg); + packet->seq = dev->seq++; + packet->len = sizeof(*msg); - memcpy(&packet.msg, msg, sizeof(*msg)); - packet.msg.len = 0; + *pkt_msg = *msg; + pkt_msg->len = 0; - cn_netlink_send(&packet.cn, 0, 0, GFP_KERNEL); + cn_netlink_send(packet, 0, 0, GFP_KERNEL); } static void w1_send_slave(struct w1_master *dev, u64 rn)