From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f179.google.com (mail-qk1-f179.google.com [209.85.222.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8FBB326FA60 for ; Fri, 10 Apr 2026 19:03:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775847834; cv=none; b=FVy64k7vMb5wz+IAU9GyDgzNGBFIWytud5iTe1ydBh4A1O/5bcN+F0OX6HmicrBmngE/9r8udExgaNQDCngCaCpxyTdcegbyq539dPukZUoGonkrAXPwAfdMzFuzR9VcYvx9QrtLBEdTJxXSWbz2u8Rm54OFwHLUBssm/NQLjgM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775847834; c=relaxed/simple; bh=0/ZauZOQB/NP1QcAH+PDITEaXUC773OeN19DfxcW1yQ=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=DWGhV0/EajnMvpL+T477ZKRrVbqen876HsNpXtY2jkZu0AE4Lf2fCKzO9oJeZV5je0kE918BE9PfvuCvMK87GmhtAmu7SdIchL34BedwwmDAZq3hD2k4ik2YvgfQ/lEWF8HDfG5ZLIzOvCsaAuhLB8GuFjaRjnklAAjV2sKu2Q4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=RgHxDIcx; arc=none smtp.client-ip=209.85.222.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="RgHxDIcx" Received: by mail-qk1-f179.google.com with SMTP id af79cd13be357-8c6f21c2d81so178176285a.2 for ; Fri, 10 Apr 2026 12:03:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1775847832; x=1776452632; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=EMSX8d1QgLZUoJnKt34AnkG63ZeJBVmP3ekDSJT4BDs=; b=RgHxDIcxGOYr5ijdsrNYCwn5BD85092DDYdqC/7CwkPtJgKSDmZOhLYci8rXuzqvgW gAd90GtFj20TIdlt992pYhfRDMTLxEjOmbQh1pUHLw/Gi3fqZGEeVuzv8k8pWvm3obdK erWR3A6dG/UFFhiApZBAU+j4YvVpIHTUFP06hHh3zCoVzT9MNxaKCbPtDcjJNkwI3eMV thpZX9fucFJsn2ldFAUklkoYJbro9ou8pz8/fK8ShDcJv4fTR7/1145/dKo0V52uxFOR gxUhzvKZvSGurqRpKhh0ap+mzyPp68rSvtblK4vwLjo1QUhP/Q++2WjrJNohF3Qif+bs rkMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775847832; x=1776452632; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=EMSX8d1QgLZUoJnKt34AnkG63ZeJBVmP3ekDSJT4BDs=; b=K/M7+yd/75kSsep9Za81NplFu19gQ6tqZ7YZn0RGjFkjZiU4BNG7q/pVHrr9qgkldX f+Eg2kkm2wCL3JObLTxPXn1fwf4qz6LiyawygFHbljv193wimTDC+SeoBks4bMufzG05 O0nNYKxxx/yr8zMitg0CfBhMtfkJWywXv8HTRS59vmOG/mEBO2vJyI7pFVjzdaOngpjo Hmquf1fY+uwtEzo8JPChKzPXxRP4dsL1VMVO/spupe7PxFjglS9cRMcHhxLmcWvv0IkI 4xmF6yUSEgSs48L1ti/772qdwMcmfZcfq5j0ms6y9MVyIo8N1mR4xStdtfxOzBRPBxCD M5tw== X-Gm-Message-State: AOJu0YwNCd5dKcE0dirdAU3jxpP4e1Hbkd/iKC0XbCC0hqXLRmjwwhQX 0PqkZf6hyYhPkdEwFQ1WzPm1GC5E/RQWLCvzmGs4lsj4jdFk7sUHz6kQc2fBOw== X-Gm-Gg: AeBDieskh46C3iqPC/M36WuJFI5/yC54gO5fmz9iaJRJ3KqX82IllA6qCqwCdeU6+ql eVtFTdV99F24Wpgcjaf8jFXuAgpPdvMuLEsv+P/Mi4vePSnexSAClORX8URzJXDh/xF4AyNQkMS g8Prvj/Wy4BDQAmqhkUcSWK45dngsRY6hZnzcbCxzfF16W95jEPxOMZby8kA4L3sWjYs7xl+y7B IryUR1VdpAz6cQAyqsYTpML0djFqWuCrDIkbK/Qar99wZyZU1KnCEu40+BeTv3nsrYc2JUZeMn9 pu/RtPlEk8uHeseS6TdytNZ7AKA0lfSiP6eSAMFQ1WTgcmDcuyxaqah0q2xxcCEfTePvG5UP5DF 64OArrUkRkdpll7hOf50xnhlnpRmhfhwsg76xZZYPEOpelLPmpB0OXvH3Fw7tjxKIoaWK4l/ov4 70buh0J4m5FLIgpiMLzSnUKc7TQOtsSZH/mxpkpvEgbmUYNc1iSLe/saYaTFaHQrL1VFiYbbASA kn8BaAB+iSiGbJHozQXxC2pO5rHpotQesM4PoRH80qD8bAG11tK7gpk5X0AOt3x X-Received: by 2002:a05:620a:2589:b0:8d9:5463:132b with SMTP id af79cd13be357-8ddcf6b5cadmr626066785a.49.1775847832034; Fri, 10 Apr 2026 12:03:52 -0700 (PDT) Received: from wsfd-netdev58.anl.eng.rdu2.dc.redhat.com ([66.187.232.140]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-8ac84a47a0dsm30598726d6.22.2026.04.10.12.03.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Apr 2026 12:03:51 -0700 (PDT) From: Xin Long To: network dev , linux-sctp@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, Eric Dumazet , Paolo Abeni , Simon Horman , Marcelo Ricardo Leitner , Florian Westphal , Yi Chen Subject: [PATCH net 0/2] sctp: fix a vtag verification failure caused by stale INITs Date: Fri, 10 Apr 2026 14:59:15 -0400 Message-ID: X-Mailer: git-send-email 2.47.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Similar to Scenario B in commit 8e56b063c865 ( netfilter: handle the connecting collision properly in nf_conntrack_proto_sctp"): Scenario B: INIT_ACK is delayed until the peer completes its own handshake 192.168.1.2 > 192.168.1.1: sctp (1) [INIT] [init tag: 3922216408] 192.168.1.1 > 192.168.1.2: sctp (1) [INIT] [init tag: 144230885] 192.168.1.2 > 192.168.1.1: sctp (1) [INIT ACK] [init tag: 3922216408] 192.168.1.1 > 192.168.1.2: sctp (1) [COOKIE ECHO] 192.168.1.2 > 192.168.1.1: sctp (1) [COOKIE ACK] 192.168.1.1 > 192.168.1.2: sctp (1) [INIT ACK] [init tag: 3914796021] * There is another case: Scenario F: INIT is delayed until the peer completes its own handshake 192.168.1.2 > 192.168.1.1: sctp (1) [INIT] [init tag: 3922216408] (OVS upcall) 192.168.1.1 > 192.168.1.2: sctp (1) [INIT] [init tag: 144230885] 192.168.1.2 > 192.168.1.1: sctp (1) [INIT ACK] [init tag: 3922216408] 192.168.1.1 > 192.168.1.2: sctp (1) [COOKIE ECHO] 192.168.1.2 > 192.168.1.1: sctp (1) [COOKIE ACK] 192.168.1.2 > 192.168.1.1: sctp (1) [INIT] [init tag: 3922216408] (delayed) 192.168.1.1 > 192.168.1.2: sctp (1) [INIT ACK] [init tag: 3914796021] * In this case, the delayed INIT (e.g. due to OVS upcall) is recorded by conntrack, which prevents vtag verification from dropping the unexpected INIT-ACK in nf_conntrack_sctp_packet(): vtag = ct->proto.sctp.vtag[!dir]; if (!ct->proto.sctp.init[!dir] && vtag && vtag != ih->init_tag) goto out_unlock; This happens because ct->proto.sctp.init[!dir] is set by the delayed INIT, even though it is stale. Fix this in two parts: - In netfilter: Do not record INITs whose init_tag matches the peer vtag, as they carry no new handshake state in the 1st patch. - In SCTP: Prevent endpoints from responding to such INITs with INIT-ACK, ensuring correctness even when middleboxes lack the netfilter fix in the 2nd patch. A follow-up selftest for this scenario will be posted in a separate patch by Yi Chen. Xin Long (2): netfilter: skip recording stale or retransmitted INIT sctp: discard stale INIT after handshake completion net/netfilter/nf_conntrack_proto_sctp.c | 10 +++++++--- net/sctp/sm_statefuns.c | 6 ++++++ 2 files changed, 13 insertions(+), 3 deletions(-) -- 2.47.1