From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.126.com (m16.mail.126.com [117.135.210.6]) (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 C051A1DD525; Mon, 13 Apr 2026 08:04:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.6 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776067477; cv=none; b=PJqx49OnoIyT/SwXon+XgL8bNTLoKlh0LUKdIoPLQuLTpYsU2vorUnli5/b6tWFS6Jtj4KCMBWDAa4W+m00wluEdrXyCiQOlHrPdaAp7NXQbYiewwfAbwsz81dhybbyljup+8rdbjhXCzjFTaIrzHhuV3/mFVd9283GeAXRHpgI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776067477; c=relaxed/simple; bh=XrQXo6XMhykepeRVxPMIsG+HJmrNavK7m6d11VND484=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=eLbRdOayX0NT38Zr6KPrbWVClEIUZcrVRhqwzLI6Bc3D4kr/+HK70IDJvS3Dr7DtESxoZTlLYUDpF2aPqJfv+t+ipqR+Iq4b9sEFrCGmg/vHWgQxM1GRUj1PQ2gK244AyFdatzJMrNoqFmWW0b4pWQUby49/KtpOmPDFI3aZROg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com; spf=pass smtp.mailfrom=126.com; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b=HBI81EW2; arc=none smtp.client-ip=117.135.210.6 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=126.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b="HBI81EW2" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=/a u4QYNETB6YPLLfe9q3AVHuigBjp3RH3DP3ODwItXQ=; b=HBI81EW2MR8GiW3ZEV cPnW95tg7DBNUUzO3ea1roA1Tsd2KDDCDqu8cQObb3Q5ABH6XWXcBcUISxifzTSi hGqCPnyx++YdQFT9xCuX2LYj+zRC9SH57jshIYLR0UJRG5kkHXRcKHyMq0pa89WE UfW7ZZRKhcjHrdkFOmuorWMHw= Received: from YUANZM2-F4WK0J3.lenovo.com (unknown []) by gzsmtp5 (Coremail) with SMTP id QCkvCgD3P3VXo9xphRR+Cw--.61877S2; Mon, 13 Apr 2026 16:03:35 +0800 (CST) From: wit_yuan To: jk@codeconstruct.com.au Cc: yuanzhaoming901030@126.com, yuanzm2@lenovo.com, matt@codeconstruct.com.au, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next v3] net: mctp: don't require received header reserved bits to be zero Date: Mon, 13 Apr 2026 16:03:33 +0800 Message-Id: <20260413080333.73086-1-yuanzhaoming901030@126.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID:QCkvCgD3P3VXo9xphRR+Cw--.61877S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxAFW8urW5uFW5JFy3GFWUtwb_yoW5XF1rpF 1UKayj9FWkKry7Kw4kAan5ZwnYgws5Ka43Cr4Igw4Iy3ZIgr18WFy0kr1UJr1DurZrGF93 X3yag345X3ZrXF7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0zEtxhtUUUUU= X-CM-SenderInfo: h1xd065kdrzxtqjziiqqtqqiyswou0bp/xtbBsBiQm2nco1hbogAA3U From: Yuan Zhaoming >From the MCTP Base specification (DSP0236 v1.2.1), the first byte of the MCTP header contains a 4 bit reserved field, and 4 bit version. On our current receive path, we require those 4 reserved bits to be zero, but the 9500-8i card is non-conformant, and may set these reserved bits. DSP0236 states that the reserved bits must be written as zero, and ignored when read. While the device might not conform to the former, we should accept these message to conform to the latter. Relax our check on the MCTP version byte to allow non-zero bits in the reserved field. Signed-off-by: Yuan Zhaoming --- v2: https://lore.kernel.org/netdev/20260410144339.0d1b289a@kernel.org/T/#t v1: https://lore.kernel.org/netdev/ff147a3f0d27ef2aa6026cc86f9113d56a8c61ac.camel@codeconstruct.com.au/T/#t --- include/net/mctp.h | 3 +++ net/mctp/route.c | 8 ++++++-- 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/include/net/mctp.h b/include/net/mctp.h index e1e0a69..d8bf907 100644 --- a/include/net/mctp.h +++ b/include/net/mctp.h @@ -26,6 +26,9 @@ struct mctp_hdr { #define MCTP_VER_MIN 1 #define MCTP_VER_MAX 1 +/* Definitions for ver field */ +#define MCTP_HDR_VER_MASK GENMASK(3, 0) + /* Definitions for flags_seq_tag field */ #define MCTP_HDR_FLAG_SOM BIT(7) #define MCTP_HDR_FLAG_EOM BIT(6) diff --git a/net/mctp/route.c b/net/mctp/route.c index e69c6f7..62517c9 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -439,6 +439,7 @@ static int mctp_dst_input(struct mctp_dst *dst, struct sk_buff *skb) struct mctp_hdr *mh; unsigned int netid; unsigned long f; + u8 ver; u8 tag, flags; int rc; @@ -467,7 +468,8 @@ static int mctp_dst_input(struct mctp_dst *dst, struct sk_buff *skb) netid = mctp_cb(skb)->net; skb_pull(skb, sizeof(struct mctp_hdr)); - if (mh->ver != 1) + ver = mh->ver & MCTP_HDR_VER_MASK; + if (ver < MCTP_VER_MIN || ver > MCTP_VER_MAX) goto out; flags = mh->flags_seq_tag & (MCTP_HDR_FLAG_SOM | MCTP_HDR_FLAG_EOM); @@ -1316,6 +1318,7 @@ static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev, struct mctp_skb_cb *cb; struct mctp_dst dst; struct mctp_hdr *mh; + u8 ver; int rc; rcu_read_lock(); @@ -1334,7 +1337,8 @@ static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev, /* We have enough for a header; decode and route */ mh = mctp_hdr(skb); - if (mh->ver < MCTP_VER_MIN || mh->ver > MCTP_VER_MAX) + ver = mh->ver & MCTP_HDR_VER_MASK; + if (ver < MCTP_VER_MIN || ver > MCTP_VER_MAX) goto err_drop; /* source must be valid unicast or null; drop reserved ranges and -- 2.43.0