From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Fw: [Bug 105091] New: ICMP unreachable is not sent when receiving GRE packets on device that has no tunnel interface Date: Sun, 27 Sep 2015 18:06:14 -0700 Message-ID: <20150927180614.52ac9154@urahara> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from mail-pa0-f42.google.com ([209.85.220.42]:34912 "EHLO mail-pa0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753807AbbI1BGK (ORCPT ); Sun, 27 Sep 2015 21:06:10 -0400 Received: by pacfv12 with SMTP id fv12so161034535pac.2 for ; Sun, 27 Sep 2015 18:06:10 -0700 (PDT) Received: from urahara (static-50-53-82-155.bvtn.or.frontiernet.net. [50.53.82.155]) by smtp.gmail.com with ESMTPSA id u1sm15769645pbz.56.2015.09.27.18.06.09 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 27 Sep 2015 18:06:09 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Begin forwarded message: Date: Sun, 27 Sep 2015 22:42:34 +0000 From: "bugzilla-daemon@bugzilla.kernel.org" To: "shemminger@linux-foundation.org" Subject: [Bug 105091] New: ICMP unreachable is not sent when receiving GRE packets on device that has no tunnel interface https://bugzilla.kernel.org/show_bug.cgi?id=105091 Bug ID: 105091 Summary: ICMP unreachable is not sent when receiving GRE packets on device that has no tunnel interface Product: Networking Version: 2.5 Kernel Version: 4.2 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: low Priority: P1 Component: IPV4 Assignee: shemminger@linux-foundation.org Reporter: isaac.lee@alliedtelesis.co.nz Regression: No Created attachment 188691 --> https://bugzilla.kernel.org/attachment.cgi?id=188691&action=edit fix patch This used to work in version 3.9. In file ip_gre.c, when a GRE packet is received and tunnel lookup returned NULL (ie, no such interface), ipgre_rcv() calls icmp_send() to respond with port unreachable message. In the latest version, gre_demux.c tries to do the same thing in gre_cisco_rcv(), but icmp_send fails because skb dst entry has been dropped (during parse_gre_header() -> iptunnel_pull_header() -> skb_dst_drop(skb);) prior to calling icmp_send, causing icmp_send to return early due to rt is NULL. A fix patch is attached. -- You are receiving this mail because: You are the assignee for the bug.