From nobody Fri Oct 18 08:33:22 2024 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 AF1934C91 for ; Tue, 4 Jun 2024 15:12:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717513970; cv=none; b=kMN1K2HNpsGKIOeD4pqzH16Q9PDehnfLT+fk+bK2V+qIlbcW4ArmyjaarRF2gYgNNiYLr/zxoHQlKTqP76GOiUd5cErJ8Bop98N3oYE+c9P/ukBBNVcM1o9bqwJjLKNCDrgiqNVtc3BV4QZApt7Ta12ZnCXpAp2eVsLZPAuO6pI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717513970; c=relaxed/simple; bh=4mTIPnVDqRAWaWo2P3xfyXByKlvb+qMN3xsNPaQ8GGM=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; b=CZonkshNsE5rHS8gfChdl2x1pBVVxEe0Tugr+Gupmh1gPRKLxRQrH94wd4pB8FOhe/dv5lW1BPXyopS8Hk92fY84fwgZJcKzUWaerkB4ttbYxYnKz1IG6Qe24LH6BoUW91KbH05nN7xPMbcr84tpERgG6x/YDv3vWLREyag4IjA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=eyL/RXmu; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="eyL/RXmu" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1717513967; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=qvJ+E+cNvqgeDmz68puB1pObXsq4qGK+Yu025xgHkzs=; b=eyL/RXmuhaIVkU+B1K72DUEqrdMxALG70VDL9g5JJCDIRprLJMGPxweNv+5F71sGF5S2Mk pnuRM7imVfizEgnqdXE7NGMzpKVm7DJiAKfbp3iwa05S8GmbxalnPAtqp9jg47uNJ4+adN TyE82w4rcVdBmH7dXXCDPzRSYfsCGJs= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-556-w5POvcGyNXW2ob5G6TxQ_Q-1; Tue, 04 Jun 2024 11:12:46 -0400 X-MC-Unique: w5POvcGyNXW2ob5G6TxQ_Q-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 45059185A78E for ; Tue, 4 Jun 2024 15:12:44 +0000 (UTC) Received: from gerbillo.redhat.com (unknown [10.45.225.192]) by smtp.corp.redhat.com (Postfix) with ESMTP id C66B91C060D2 for ; Tue, 4 Jun 2024 15:12:43 +0000 (UTC) From: Paolo Abeni To: mptcp@lists.linux.dev Subject: [PATCH mptcp-net] mptcp: ensure snd_una is properly initialized on connect Date: Tue, 4 Jun 2024 17:12:36 +0200 Message-ID: <61aae3730b8c35c2e0b8b70f5f2fe5170067f5c8.1717512099.git.pabeni@redhat.com> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8"; x-default="true" This is strictly related to commit fb7a0d334894 ("mptcp: ensure snd_nxt is properly initialized on connect"). It turns out that syzkaller can trigger the retransmit after fallback and before processing any other incoming packet - so that snd_una is still left uninitialized. Address the issue explicitly initializing snd_una together with snd_nxt and write_seq. Suggested-by: Mat Martineau Fixes: 8fd738049ac3 ("mptcp: fallback in case of simultaneous connect") Cc: stable@vger.kernel.org Reported-by: Christoph Paasch Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/485 Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau --- net/mptcp/protocol.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 2f8f32cd31d3..1c5b7796daaf 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -3735,6 +3735,7 @@ static int mptcp_connect(struct sock *sk, struct sock= addr *uaddr, int addr_len) =20 WRITE_ONCE(msk->write_seq, subflow->idsn); WRITE_ONCE(msk->snd_nxt, subflow->idsn); + WRITE_ONCE(msk->snd_una, subflow->idsn); if (likely(!__mptcp_check_fallback(msk))) MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEACTIVE); =20 --=20 2.43.2