From mboxrd@z Thu Jan 1 00:00:00 1970 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 0AE6C3F44CC; Fri, 15 May 2026 16:08:50 +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=1778861330; cv=none; b=SI5F/yDLI34hjSShveJC7yuyoyEB5UOdSpmkMEYyXGVU8ppS2Wd2dHPUhzLzRaGt6o695yaKHnEyv0CJJexKzY17kOL6NrkFpNrNR+6Ab6gc7SM2HEuHDSp4bbZRrz7ZIQjVpMKUD4BWUZrz6pQDgfmGVSh8eTyGbtWxrS5iuqg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778861330; c=relaxed/simple; bh=YbQTh3YP4l4mvW5FAObBomk73zQQcr1vIo2icw0KcgI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AuTjwfleOrFjKNg2g13zSGP1xr6xxzhSAW7Kfoc4POyYGTOTKvTXFVrqo+tsHpCr0ebokZVFaru/y35FQegHVcM41S2tG6dRDzUK45RKt3t48ygmbIQ3ZxMqe4NoAxqGVuWLtaDGZ3wR9+McBzPgGhS+2Z98mTAKZ6sI/RbTBsM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=oP+DeMYT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="oP+DeMYT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94A36C2BCB0; Fri, 15 May 2026 16:08:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778861329; bh=YbQTh3YP4l4mvW5FAObBomk73zQQcr1vIo2icw0KcgI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oP+DeMYTOQMT7DEOygOT8ycozqMvQwEBm9X8wv+lGUX89787v1ofIARux99QfWYqW YOS64lhaoKRAoketfzhXeRm+oFWemNU9BI0kRf8uDXcygoWoV30pFodKghW0vm0sib BdpTEiuditvNSN0mr4zwF+KIjqyFqu4ODToVivNA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Matthieu Baerts (NGI0)" , Shardul Bankar , Jakub Kicinski Subject: [PATCH 6.6 285/474] mptcp: use MPTCP_RST_EMPTCP for ACK HMAC validation failure Date: Fri, 15 May 2026 17:46:34 +0200 Message-ID: <20260515154721.168163442@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260515154715.053014143@linuxfoundation.org> References: <20260515154715.053014143@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shardul Bankar commit a6da02d4c00fdda2417e42ad2b762a9209e6cc49 upstream. 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) Link: https://patch.msgid.link/20260501-net-mptcp-misc-fixes-7-1-rc3-v1-2-b70118df778e@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/mptcp/subflow.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -885,7 +885,7 @@ create_child: if (!subflow_hmac_valid(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; }