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 B700A145FFC; Wed, 7 Feb 2024 21:27:45 +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=1707341265; cv=none; b=giTq6EA59AcW6c4Yiyo0X9Rz9smJrBGI7NLvByP4cVq6pdXpDM5f75FFo8zK/6HiHuCQfsQ22DivL97lWwLnXOK4S+BRGZuDwXFrfgy6upws469U5zjbtmasxsKcP0UXmB4sT+pYzqObNCi8pk2q4bUfWfcImEIGOnkKaRhGEpQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707341265; c=relaxed/simple; bh=E0n0WtPXjjLzD4BIqomJfWF09IPPkuCcdD6GAPIpkhw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=T/LJO1WHA1ClitZEqZAPsVqUS2bLmyiGODdk4LyaF4zLWFDFPzKEH3X20XzYt+oLCTfnkppQdSMQHa6fdZXF7oFRs4+jc0KwFnKe/0HkllJNMnl88dxp1Kqxe5mpMSV/kcnHNcYmtIxTIQl4k3pwW38pyxCNxMq22vfLVs1tGjo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WjOy17k3; 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="WjOy17k3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 883BAC43394; Wed, 7 Feb 2024 21:27:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707341265; bh=E0n0WtPXjjLzD4BIqomJfWF09IPPkuCcdD6GAPIpkhw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WjOy17k3oIGAogrz0mGTuxqzvwAe1dVbwBd/EUSDpSoqklXkCLFDsiT3ENV9PDBZt AOcBln1MVdWxoYcGtUq1CnAsjxkDEpqLVN7De0MJ/dwpR0DoV3KnlSxf78wGbtLAZG Oe0kLVbK7HwLCQABIW7vVabGfdLyHiPlcQVmLRBYZji07rYQztqL6uLr50GqYNAKSS 9qXganRp6bcTblr2d/GqDtjxHOy7q+3CgWln5hTpgXIkhs/I7rqm1OHz9267yhzVwy 6m44X1dHfTSrPcHqYl+25J+d5dAHjOv8E9ljmJYzXtBylmzSZ2I9/sYHzxHHBhEH// Q8LSfQr3kghzg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xin Long , Pablo Neira Ayuso , Sasha Levin , kadlec@netfilter.org, fw@strlen.de, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 6/7] netfilter: conntrack: check SCTP_CID_SHUTDOWN_ACK for vtag setting in sctp_new Date: Wed, 7 Feb 2024 16:27:30 -0500 Message-ID: <20240207212732.4627-6-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240207212732.4627-1-sashal@kernel.org> References: <20240207212732.4627-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.4.268 Content-Transfer-Encoding: 8bit From: Xin Long [ Upstream commit 6e348067ee4bc5905e35faa3a8fafa91c9124bc7 ] The annotation says in sctp_new(): "If it is a shutdown ack OOTB packet, we expect a return shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8)". However, it does not check SCTP_CID_SHUTDOWN_ACK before setting vtag[REPLY] in the conntrack entry(ct). Because of that, if the ct in Router disappears for some reason in [1] with the packet sequence like below: Client > Server: sctp (1) [INIT] [init tag: 3201533963] Server > Client: sctp (1) [INIT ACK] [init tag: 972498433] Client > Server: sctp (1) [COOKIE ECHO] Server > Client: sctp (1) [COOKIE ACK] Client > Server: sctp (1) [DATA] (B)(E) [TSN: 3075057809] Server > Client: sctp (1) [SACK] [cum ack 3075057809] Server > Client: sctp (1) [HB REQ] (the ct in Router disappears somehow) <-------- [1] Client > Server: sctp (1) [HB ACK] Client > Server: sctp (1) [DATA] (B)(E) [TSN: 3075057810] Client > Server: sctp (1) [DATA] (B)(E) [TSN: 3075057810] Client > Server: sctp (1) [HB REQ] Client > Server: sctp (1) [DATA] (B)(E) [TSN: 3075057810] Client > Server: sctp (1) [HB REQ] Client > Server: sctp (1) [ABORT] when processing HB ACK packet in Router it calls sctp_new() to initialize the new ct with vtag[REPLY] set to HB_ACK packet's vtag. Later when sending DATA from Client, all the SACKs from Server will get dropped in Router, as the SACK packet's vtag does not match vtag[REPLY] in the ct. The worst thing is the vtag in this ct will never get fixed by the upcoming packets from Server. This patch fixes it by checking SCTP_CID_SHUTDOWN_ACK before setting vtag[REPLY] in the ct in sctp_new() as the annotation says. With this fix, it will leave vtag[REPLY] in ct to 0 in the case above, and the next HB REQ/ACK from Server is able to fix the vtag as its value is 0 in nf_conntrack_sctp_packet(). Signed-off-by: Xin Long Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nf_conntrack_proto_sctp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c index e7545bcca805..6b2a215b2786 100644 --- a/net/netfilter/nf_conntrack_proto_sctp.c +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -299,7 +299,7 @@ sctp_new(struct nf_conn *ct, const struct sk_buff *skb, pr_debug("Setting vtag %x for secondary conntrack\n", sh->vtag); ct->proto.sctp.vtag[IP_CT_DIR_ORIGINAL] = sh->vtag; - } else { + } else if (sch->type == SCTP_CID_SHUTDOWN_ACK) { /* If it is a shutdown ack OOTB packet, we expect a return shutdown complete, otherwise an ABORT Sec 8.4 (5) and (8) */ pr_debug("Setting vtag %x for new conn OOTB\n", -- 2.43.0