netdev - Fw: [Bug 105091] New: ICMP unreachable is not sent when receiving GRE packets on device that has no tunnel interface

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <20150927180614.52ac9154@urahara>
Date:	Sun, 27 Sep 2015 18:06:14 -0700
From:	Stephen Hemminger <stephen@...workplumber.org>
To:	netdev@...r.kernel.org
Subject: Fw: [Bug 105091] New: ICMP unreachable is not sent when receiving
 GRE packets on device that has no tunnel interface



Begin forwarded message:

Date: Sun, 27 Sep 2015 22:42:34 +0000
From: "bugzilla-daemon@...zilla.kernel.org" <bugzilla-daemon@...zilla.kernel.org>
To: "shemminger@...ux-foundation.org" <shemminger@...ux-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@...ux-foundation.org
          Reporter: isaac.lee@...iedtelesis.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.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html