From nobody Sat Jun 20 20:54:51 2026 Received: from m16.mail.126.com (m16.mail.126.com [220.197.31.6]) (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 84C6C346AFB; Fri, 10 Apr 2026 06:17:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.6 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775801870; cv=none; b=k7ZkWmp9TG+nAFDMEFqo/JAKBT19P+Sao+7UkYduDVow2FmKGsDfgAx1HZXY6a/Tdt/LwtFzw+FjDq9mmbz5E73TYfU2wEen/66mloxAGkJuC5Gk59BpqU1oS7eGH8HwtMCLNIUMUJp60ZM0d+28gAZsoYLW2rr08srwdp3ArkQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775801870; c=relaxed/simple; bh=k7Bl40ND0izrraTo2iqYR9VWnNM9qb0c1MGMEVehBv8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=TQu/6kDzmBD4Ll6Osq+/efzHK/8bMVEFcAb+cLSzqt52sM8n75E5/WrjygXbksxE6N2/PacsibaIbHN654pDrxtd40I4Q2UsrmncO6rH8bk+ORBT1+74L/dZhaf6oO+WfllUqyBKe4Ekv2XJwTH9WkZAhpw62JY68egnxer+EFk= 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=SEYZUIFR; arc=none smtp.client-ip=220.197.31.6 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="SEYZUIFR" 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=eP lj0l3Pj4+bjFqZ6o5saRtTsk6tAaSXaEymjlhAFEA=; b=SEYZUIFRvUlOyUnziw cz7+zYkZh2aARduBXPkN4S0EkW4aa3Q5hIsJPOEFz9DGcORzjT2C6PjxZxhmBA/d cCOU3misgjHasRsR3yRBEFDzuVDcB8S4+OPTJ4Eg0+e2HecN1f7Tcs/igUv+t25a 9Nr2B2pdqrFx9GGff+bwukmVA= Received: from YUANZM2-F4WK0J3.lenovo.com (unknown []) by gzga-smtp-mtada-g0-0 (Coremail) with SMTP id _____wD3B_nhldhpioNMBA--.57048S3; Fri, 10 Apr 2026 14:17:13 +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 next-next v2] net:mctp: fix setting mctp hdr ver reserved field cause data dropped Date: Fri, 10 Apr 2026 14:17:03 +0800 Message-Id: <20260410061703.3547-2-yuanzhaoming901030@126.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260410061703.3547-1-yuanzhaoming901030@126.com> References: <20260410061703.3547-1-yuanzhaoming901030@126.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wD3B_nhldhpioNMBA--.57048S3 X-Coremail-Antispam: 1Uf129KBjvJXoW7WFW8Gw1UKrW8XFWkGFyUWrg_yoW8Cw4UpF 1DKrW09rWkKFW2gr4kAaykXanYg3s8Ka4Uur4Sgw40qwnxXr18GFWIkr1UJw18urZ7KF93 JrWY9w1UJw47XF7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07UzOJ5UUUUU= X-CM-SenderInfo: h1xd065kdrzxtqjziiqqtqqiyswou0bp/xtbBsQkwO2nYlelHEwAA3q Content-Type: text/plain; charset="utf-8" From: Yuan Zhaoming from spec dsp0236_1.2.1.pdf page 26, the mctp header contains the RSVD(4bit) and Hdr version(4 bit). mctp_pkttype_receive invoke mctp_hdr, and get mh->ver whole byte=20 compare the MCTP_VER_MIN, MCTP_VER_MAX. the reserver bits may be by=20 misleading used. one type hba card will set pcie vdm header Pad Len the same with RSVD bit, this will not work on mctp kernel solution. Signed-off-by: Yuan Zhaoming --- include/net/mctp.h | 1 + net/mctp/route.c | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/include/net/mctp.h b/include/net/mctp.h index f481007a6..1392fafe7 100644 --- a/include/net/mctp.h +++ b/include/net/mctp.h @@ -35,6 +35,7 @@ struct mctp_hdr { #define MCTP_HDR_SEQ_MASK GENMASK(1, 0) #define MCTP_HDR_TAG_SHIFT 0 #define MCTP_HDR_TAG_MASK GENMASK(2, 0) +#define MCTP_HDR_VER_MASK GENMASK(3, 0) =20 #define MCTP_INITIAL_DEFAULT_NET 1 =20 diff --git a/net/mctp/route.c b/net/mctp/route.c index 56c441e90..aa0e89d67 100644 --- a/net/mctp/route.c +++ b/net/mctp/route.c @@ -464,7 +464,7 @@ static int mctp_dst_input(struct mctp_dst *dst, struct = sk_buff *skb) netid =3D mctp_cb(skb)->net; skb_pull(skb, sizeof(struct mctp_hdr)); =20 - if (mh->ver !=3D 1) + if (((mh->ver & MCTP_HDR_VER_MASK)) < MCTP_VER_MIN || (mh->ver & MCTP_HDR= _VER_MASK) > MCTP_VER_MAX) goto out; =20 flags =3D mh->flags_seq_tag & (MCTP_HDR_FLAG_SOM | MCTP_HDR_FLAG_EOM); @@ -1345,7 +1345,7 @@ static int mctp_pkttype_receive(struct sk_buff *skb, = struct net_device *dev, =20 /* We have enough for a header; decode and route */ mh =3D mctp_hdr(skb); - if (mh->ver < MCTP_VER_MIN || mh->ver > MCTP_VER_MAX) + if (((mh->ver & MCTP_HDR_VER_MASK)) < MCTP_VER_MIN || (mh->ver & MCTP_HDR= _VER_MASK) > MCTP_VER_MAX) goto err_drop; =20 /* source must be valid unicast or null; drop reserved ranges and --=20 2.43.0