[lwip-devel] [patch #9217] IPv6 patches: reassembly, length check improvements

[David van Moolenbroek]

URL:
  <http://savannah.nongnu.org/patch/?9217>

                 Summary: IPv6 patches: reassembly, length check improvements
                 Project: lwIP - A Lightweight TCP/IP stack
            Submitted by: dcvmoole
            Submitted on: Mon 09 Jan 2017 09:53:35 PM GMT
                Category: IPv6
                Priority: 5 - Normal
                  Status: None
                 Privacy: Public
             Assigned to: None
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
         Planned Release: None

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Details:

My attempt to receive a 65535-byte IPv6 packet ended up triggering the new
overflow check from patch #9209, and my attempt to fix the underlying cause
brought up even more issues..

0001-IPv6-fragment-reassembly-fixes: This patch 1) changes the IPv6
fragmentation code to support reassembly of packets with "unfragmentable"
extension headers [*]; 2) stops private data structures (garbage) from being
included in ICMPv6 reassembly-timed-out messages; and, 3) implements
reassembly correctly even for very large packets. I feel obliged to add that
this patch is somewhat under-tested as I have no effective way of testing some
of it, but I contend that it is enough of a structural improvement that it is
worth merging either way. Also, it does resolve my original problem.. :) If
necessary I can work on splitting it into multiple patches. All feedback
welcome etc

0002-ip6-improve-length-checks-for-extension-headers: This patch fixes a few
"potential read beyond buffer end" cases.

[*] as far as I can tell, this was supported originally (as per RFC
requirements) but was lost as part of the IPV6_FRAG_COPYHEADER work, which
structurally assumes that the header before the fragment header is the ipv6
header itself.



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File Attachments:


-------------------------------------------------------
Date: Mon 09 Jan 2017 09:53:35 PM GMT  Name:
0001-IPv6-fragment-reassembly-fixes.patch  Size: 18kB   By: dcvmoole

<http://savannah.nongnu.org/patch/download.php?file_id=39416>
-------------------------------------------------------
Date: Mon 09 Jan 2017 09:53:35 PM GMT  Name:
0002-ip6-improve-length-checks-for-extension-headers.patch  Size: 5kB   By:
dcvmoole

<http://savannah.nongnu.org/patch/download.php?file_id=39417>

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