Re: OOPS, ip -f inet6 route get fec0::1, linux-2.6.26, ip6_route_output, rt6_fill_node+0x175

[Eugene Teo <eteo@redhat.com>]

Brian Haley wrote:
> Alexey Dobriyan wrote:
>> On Thu, Aug 07, 2008 at 07:00:56PM +0200, John Gumb wrote:
>>> Scenario: no ipv6 default route set.
>>
>>> # ip -f inet6 route get fec0::1
>>>
>>> BUG: unable to handle kernel NULL pointer dereference at 00000000
>>> IP: [<c0369b85>] rt6_fill_node+0x175/0x3b0
>>> EIP is at rt6_fill_node+0x175/0x3b0
>>
>> 0xffffffff80424dd3 is in rt6_fill_node (net/ipv6/route.c:2191).
>> 2186                    } else
>> 2187    #endif
>> 2188                            NLA_PUT_U32(skb, RTA_IIF, iif);
>> 2189            } else if (dst) {
>> 2190                    struct in6_addr saddr_buf;
>> 2191      ====>         if
>> (ipv6_dev_get_saddr(ip6_dst_idev(&rt->u.dst)->dev,
>>                            ^^^^^^^^^^^^^^^^^^^^^^^^
>>                                    NULL
>>
>> 2192                                           dst, 0, &saddr_buf) == 0)
>> 2193                            NLA_PUT(skb, RTA_PREFSRC, 16,
>> &saddr_buf);
>> 2194            }
> 
> The commit that changed this can't be reverted easily, but the patch
> below works for me.
> 
> Fix NULL de-reference in rt6_fill_node() when there's no IPv6 input
> device present in the dst entry.
> 
> Signed-off-by: Brian Haley <brian.haley@hp.com>

Cc: Stable <stable@kernel.org>

Eugene