Bug 1399764

Summary: Segfault with 'ip6 nexthdr ipv6-frag'
Product: Red Hat Enterprise Linux 7 Reporter: Phil Sutter <psutter>
Component: nftablesAssignee: Phil Sutter <psutter>
Status: CLOSED ERRATA QA Contact: Vaclav Danek <vdanek>
Severity: medium Docs Contact:
Priority: medium    
Version: 7.4CC: atragler, kvolny, mleitner, sukulkar, todoleza, vdanek
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
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Fixed In Version: nftables-0.6-4.el7 Doc Type: If docs needed, set a value
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Clone Of: Environment:
Last Closed: 2017-08-01 18:56:07 UTC Type: Bug
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Phil Sutter 2016-11-29 16:56:06 UTC
The following command crashes nft utility reproducibly:

# nft add rule ip6 test ftest ip6 nexthdr ipv6-frag counter

Analysis of the cause using gdb and looking at differences between version 0.6 and upstream (which works fine) shows we're missing the following commit:

commit 3503738f77cdbe521da1054a37f59ac2e442b4cf
Author: Florian Westphal <fw>
Date:   Mon Jun 6 21:52:28 2016 +0200

    payload: don't update protocol context if we can't find a description
    
    Since commit
    20b1131c07acd2fc ("payload: fix stacked headers protocol context tracking")
    we deref null pointer if we can't find a description for the desired
    protocol, so "ip protocol 254" crashes while testing protocols 6 or 17
    (tcp, udp) works.
    
    Also add a test case for this.
    
    Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1072
    Signed-off-by: Florian Westphal <fw>
    Acked-by: Pablo Neira Ayuso <pablo>

Comment 6 errata-xmlrpc 2017-08-01 18:56:07 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2017:2047