From nobody Tue Jun 23 23:12:00 2026 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 6BBAD421A0C; Fri, 1 May 2026 19:36:17 +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=1777664177; cv=none; b=hifro4sUK/m+ZyYVwhAMXjLYhsu6Jq9xmT4KjPBbYmX6617KSBn9sy/nakTQbSKc/QHkbE1TYsvFwkOfUFW8pkqbH9PKAopxvh+cIhv5jvrGT+pWVOxf811tFotXepvs3Mc30gC0LqJulY2MGLD2UiC1YhC/1h8rjtJe3s9Gykc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777664177; c=relaxed/simple; bh=iN/5ZWsd+G/llWYnMKfz9xNhUpeX3w53Wzqf1rHwPRg=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=DSqOxBt00+T4jYfYTYFtorRkVV4NbaT3lzChYHB+pvR13o6ouDI+etWKs7NJwT+t/kZZTfjPuzRm/YeHIdgdPvKruG6oN7ETqrb6y0YwbwCVpm3fGszmEfCorD2AP53j2u3s7d3fhK41UQAPaRQgCcNy6z6xrUVikPsk3lee080= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TDcA172B; 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="TDcA172B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94083C2BCB4; Fri, 1 May 2026 19:36:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777664177; bh=iN/5ZWsd+G/llWYnMKfz9xNhUpeX3w53Wzqf1rHwPRg=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=TDcA172B/JYXX9geY4/si/gC22N/nD5h8VNU+kxctS/fprkwk86GTivr2sTGzbyLJ kyNtotaBJYeUzHN/+M1/QpdOWTrD4Egro56fL8dOPcjnLgei2DSVTiKILpy0uSOj3s ND788sqtal+f2BpEKDJnZvLS9ZpOeMq12pfn7cSJgOrTowQfX+RBujdxnytBOiiZJx tJbDU+ACW99tL3AoviBc//7ujVyeGdRBPREn6pws6mpEoHRmxK3OeSyNMrslaTyGMW 2AKD523ErLprSR70HzlFDZX+TnEGr/cENcgyrJ9PqRoKEB63yZziHuMxf9XZM37+vM 48LuCyiPnB+QQ== From: "Matthieu Baerts (NGI0)" Date: Fri, 01 May 2026 21:35:35 +0200 Subject: [PATCH net 2/4] mptcp: use MPTCP_RST_EMPTCP for ACK HMAC validation failure Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260501-net-mptcp-misc-fixes-7-1-rc3-v1-2-b70118df778e@kernel.org> References: <20260501-net-mptcp-misc-fixes-7-1-rc3-v1-0-b70118df778e@kernel.org> In-Reply-To: <20260501-net-mptcp-misc-fixes-7-1-rc3-v1-0-b70118df778e@kernel.org> To: Mat Martineau , Geliang Tang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Florian Westphal , Gang Yan , Dmytro Shytyi Cc: netdev@vger.kernel.org, mptcp@lists.linux.dev, linux-kernel@vger.kernel.org, "Matthieu Baerts (NGI0)" , Shardul Bankar , stable@vger.kernel.org X-Mailer: b4 0.15.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=1477; i=matttbe@kernel.org; h=from:subject:message-id; bh=DOYuhrAzltfrRlUqWb1toh/VN3K8I0dgYPEc5n8ev4w=; b=owGbwMvMwCVWo/Th0Gd3rumMp9WSGDK/Mixz27Ri64T6hMVeVxc84KhdoxR7sDNXNfpHrDQf+ 5SFF7W3d5SyMIhxMciKKbJIt0Xmz3xexVvi5WcBM4eVCWQIAxenAEyE35Lhn6YpU2Qrr9mO2oyl 4aL5py45xb99yha+/My7lVpl1vsbMxj+R37a4BGxrbJJ7GLVo9tejsIPuDZW2Uzc1FIuFSpz+xs vEwA= X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 From: Shardul Bankar When HMAC validation fails on a received ACK + MP_JOIN in subflow_syn_recv_sock(), the subflow is reset with reason MPTCP_RST_EPROHIBIT ("Administratively prohibited"). This is incorrect: HMAC validation failure is an MPTCP protocol-level error, not an administrative policy denial. The mirror site on the client, in subflow_finish_connect(), already uses MPTCP_RST_EMPTCP ("MPTCP-specific error") for the same kind of HMAC failure on the SYN/ACK + MP_JOIN. Use the same reason on the server side for symmetry and accuracy. Suggested-by: Matthieu Baerts (NGI0) Fixes: 443041deb5ef ("mptcp: fix NULL pointer in can_accept_new_subflow") Cc: stable@vger.kernel.org Signed-off-by: Shardul Bankar Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) --- net/mptcp/subflow.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index bda6862264ca..d562e149606f 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -908,7 +908,7 @@ static struct sock *subflow_syn_recv_sock(const struct = sock *sk, =20 if (!subflow_hmac_valid(subflow_req, &mp_opt)) { SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKMAC); - subflow_add_reset_reason(skb, MPTCP_RST_EPROHIBIT); + subflow_add_reset_reason(skb, MPTCP_RST_EMPTCP); goto dispose_child; } =20 --=20 2.53.0