From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15A6AC1975A for ; Wed, 25 Mar 2020 15:26:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D75D620409 for ; Wed, 25 Mar 2020 15:26:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20150623.gappssmtp.com header.i=@networkplumber-org.20150623.gappssmtp.com header.b="J96/lLdW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727598AbgCYP0Y (ORCPT ); Wed, 25 Mar 2020 11:26:24 -0400 Received: from mail-pg1-f177.google.com ([209.85.215.177]:44300 "EHLO mail-pg1-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727488AbgCYP0X (ORCPT ); Wed, 25 Mar 2020 11:26:23 -0400 Received: by mail-pg1-f177.google.com with SMTP id 142so1278749pgf.11 for ; Wed, 25 Mar 2020 08:26:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:subject:message-id:mime-version :content-transfer-encoding; bh=rR/adMTP0klm0aKLJ4Jitqp8PklTDeB3TjccNpzVOcA=; b=J96/lLdWuTVY7WpLI6W/J4lqVJ6XxTF/nWn9cdmqSEUwdYkXpoeuJKaZ9xC7wua/Zq FCv+fCpuBxB+XirMZrtGRaVHS2YcMe5jNkx/HZHYq+yjiWjh0BBsea5yNPjWJ6g76tP0 BYl0ZzGbdFRfDjmHmfVbC+xbe8gVP7P5wqpOLc+mQdwxPxUCtHk07DPH1SN9uRLfzlaH HnIyTyGj0R3KL8IWKWQBJhj5m3C/HGXtZjvW/FMWR5XWBdYZz80mErlupF//z86u3zxG K1rv8LQg4RvrNPSyCBJ66bVYvQV13JTB3D4al62YECl2z3Wzan2R/qtTrpOm5ebBu45U Bz2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:mime-version :content-transfer-encoding; bh=rR/adMTP0klm0aKLJ4Jitqp8PklTDeB3TjccNpzVOcA=; b=P/gUxEQNNev6iNKAZAoFticTCeMcLFqjWA0y6B6caxb36dM15hQj00B4t+t8ITPs+F Te6xlWl648cJuBvsk525yXF1tk1Bezfbp/mdd1okdsnEOMp8555km87hrINr0fWdeWcN bTR5GNXD/M4sqORFGF6mNoMTV4TfZyBlIV5dSPSPTxF0uQTS2bTXvRr9J/rdcrD0VCTG WQrWgj3A2BkAHihH4Vh7swwcrmPwhT4kqeO82mqZp/aTcjImVi0a57zACjeEv6KFS1Md 2K6qxvOrzZ5HkmXr6dECmMFaS8pPEhj63bhHJAXZPXUsYuJBuOZS3GHn1C2Dhv5r9KPL ZWlw== X-Gm-Message-State: ANhLgQ1K0Q6eKUgZMibXHZoO8pz6ihCm3Fudr9bOZe11MhazhIRNrQvG M1YWTuvQJ+6sIYQsi3eDISGu0w5wnDrErg== X-Google-Smtp-Source: ADFU+vvBzVgfGqoqxwR5HddHWG1ykM4Yw0Eh8kSOEwhfq5Rui7YJj9e4GCLDW8CkhQLTtx+veyxiEQ== X-Received: by 2002:a63:717:: with SMTP id 23mr3753027pgh.61.1585149980832; Wed, 25 Mar 2020 08:26:20 -0700 (PDT) Received: from hermes.lan (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id x188sm19119957pfx.198.2020.03.25.08.26.20 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Mar 2020 08:26:20 -0700 (PDT) Date: Wed, 25 Mar 2020 08:26:11 -0700 From: Stephen Hemminger To: netdev@vger.kernel.org Subject: Fw: [Bug 206945] New: downgrading IPID assignment for TCP datagrams Message-ID: <20200325082611.1cb94f97@hermes.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Begin forwarded message: Date: Wed, 25 Mar 2020 08:49:38 +0000 From: bugzilla-daemon@bugzilla.kernel.org To: stephen@networkplumber.org Subject: [Bug 206945] New: downgrading IPID assignment for TCP datagrams https://bugzilla.kernel.org/show_bug.cgi?id=206945 Bug ID: 206945 Summary: downgrading IPID assignment for TCP datagrams Product: Networking Version: 2.5 Kernel Version: since kernel 3.9 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: high Priority: P1 Component: IPV4 Assignee: stephen@networkplumber.org Reporter: fengxw18@mails.tsinghua.edu.cn Regression: No Through sending a forged ICMP "Fragmentation Needed" message to the Linux host, an off-path attacker can clear the DF (Don't Fragment) flag in IP header, thus downgrading the IPID assignment for TCP datagrams from the more secure per-socket based counter to hash based counter (since kernel version 3.9). Then the attacker can detect a shared IPID counter via hash collisions, which forms a side-channel. By observing the side channel, the attacker can hijack TCP connections on the vulnerable Linux host completely off-path. -- You are receiving this mail because: You are the assignee for the bug.