From owner-freebsd-security@freebsd.org Sat Feb 3 13:47:49 2018 Return-Path: Delivered-To: freebsd-security@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 05591EEA546; Sat, 3 Feb 2018 13:47:49 +0000 (UTC) (envelope-from brahma.gdb@gmail.com) Received: from mail-io0-x230.google.com (mail-io0-x230.google.com [IPv6:2607:f8b0:4001:c06::230]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 64E5569784; Sat, 3 Feb 2018 13:47:48 +0000 (UTC) (envelope-from brahma.gdb@gmail.com) Received: by mail-io0-x230.google.com with SMTP id l17so25865342ioc.3; Sat, 03 Feb 2018 05:47:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=oD6pmxhydqnT7QO8OUygxn8XlcVh570xvCC7SjR++sw=; b=TKkRwFtnS0fvqXBO7+eImt9K7odtragesb3U+unZ5wziQ5GBIZHD6RDCZ0dybLu9Y3 H91qDRfza0MLZ9OoBZe/tWNIM+vytuhcUzkAA0ijXpm31N5a++gRzvniTLb7vQ5/Z3JB xNv+eZ/rWaUdst9UpMUGWRm+E6JOe4OUOOHQRbMTWOyZIyjP6BETGU1x75XFZVYQvD5U 0KpMzko+TZX+lrsqW7+CxfwSH3K4T8pze8Op8HE/Dgu9N1wEXD8RVs3ef0BwL3Zc+hKt gIDbFnfDhK5to+zlhfhTeVU60GHlqTscdnH6H+oGMV7vyfhWX+1j7wmu0PfzsWQoDPle Z5Eg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=oD6pmxhydqnT7QO8OUygxn8XlcVh570xvCC7SjR++sw=; b=Nu4MHyoYMcnbX+k0VjhGy0xEaBEdzIg50qTqyx5SsdqjtKYjnZ76WkpPjH+QrknuIz XeYw58HfucTMjZS5/1N4uVVEMjkEN/5pyAnDeFFGK4HbG3JBkkoz1NtrFPUsE1T0vcS2 ZctKygWux6IDpcNOdF196iXTDCwZEPDL3pJsqmDOyLzAjsHdVNmlqOtItL/pu9CSdrRe osC8JNxxD0hNq3Wo8g0eyfGCzZyeKlqD5twZXFrE8H6Lry23xeMq1HMoJcOaJsxbOZUZ kjGjBAjM7WUjbo/s+jptgOrZWXfVdmc4Nxaw9LDrtdeT3Y/Zr98i2kFQ1MtZSaKFDASu Dpjw== X-Gm-Message-State: AKwxyteK+yh1hZOv5glSBFs4Ij4izGJ1VqplJdGBTStgD5yTdeCLcaH3 yPp2mAhcLsabRzpzwEBuzIGFKRDQrQnV0KIgGgnAgg== X-Google-Smtp-Source: AH8x226mI70sw78H8ad+077muk6kkqVKBliHvWphTx76yoq7usedLvgZf3v3J3RFLYQwmkS3TkzFzkmP7mZe3JKvrnw= X-Received: by 10.107.136.201 with SMTP id s70mr46502192ioi.177.1517665667717; Sat, 03 Feb 2018 05:47:47 -0800 (PST) MIME-Version: 1.0 Received: by 10.79.46.85 with HTTP; Sat, 3 Feb 2018 05:47:47 -0800 (PST) From: Brahmanand Reddy Date: Sat, 3 Feb 2018 19:17:47 +0530 Message-ID: Subject: 'Syncookies' feature effects to generate new ISN/random with RST happens 15 seconds delay. To: FreeBSD-security@freebsd.org, freebsd-security-owner@freebsd.org X-Mailman-Approved-At: Sat, 03 Feb 2018 13:52:23 +0000 Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.25 X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 03 Feb 2018 13:47:49 -0000 Dear Experts, Recently i observed in 11.0 FreeBsd Kernel. new ISN random generating every 15 seconds. RST not happens quickly. if disable net.inet.tcp.syncookies=0 on syscntrl.conf .. RST happens quickly and generate new ISN numnber for next SYN requests. https://github.com/freebsd/freebsd/blob/master/sys/netinet/tcp_syncache.c#L1882 Could you please confirm its expected behavior about delay. have notified this issue, we have any patch please share. Thanks in Advance, Brahma