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Bugme-new Andrew Morton 2 participants 2 messages Oct 14, 2009 1 message not in the archive

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Andrew Morton

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Quoted 32 lines · On Tue, 6 Oct 2009 00:16:31 GMT [email protected] wrote:

http://bugzilla.kernel.org/show_bug.cgi?id=14330

               URL: NULL pointer dereference with arp_notify and no ip
                    address
           Summary: Kernel
           Product: Networking
           Version: 2.5
    Kernel Version: 2.6.30.8-64.fc11.x86_64
          Platform: All
        OS/Version: Linux
              Tree: Fedora
            Status: NEW
          Severity: normal
          Priority: P1
         Component: IPV4
        AssignedTo: [email protected]
        ReportedBy: [email protected]
        Regression: No

A NULL pointer dereference happens if arp_notify is enabled, no ip address is set
and the mac address changes on an interface.

Steps to reproduce:
sysctl -w net.ipv4.conf.all.arp_notify=1
ip a f dev eth0
ip l s eth0 a 02:00:00:00:00:00

It seems that in function inetdev_event (net/ipv4/devinet.c:1081) the dereference of in_dev->ifa_list->ifa_address blows up because in_dev->ifa_list is NULL.

maintainer
#2 lore raw

From: Andrew Morton <[email protected]>
Date: Tue, 13 Oct 2009 19:48:06 -0700

Quoted 2 lines

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Fixed by:

commit a21090cff296eb82b6de09304d64de466bdcaefc

Author: Stephen Hemminger <[email protected]>
Date:   Wed Oct 7 03:18:17 2009 -0700

ipv4: arp_notify address list bug

This fixes a bug with arp_notify.

If arp_notify is enabled, kernel will crash if address is changed and no IP address is assigned.
http://bugzilla.kernel.org/show_bug.cgi?id=14330

Reported-by Hannes Frederic Sowa <[email protected]>
Signed-off-by Stephen Hemminger <[email protected]>
Signed-off-by Eric Dumazet <[email protected]>
Signed-off-by David S. Miller <[email protected]>