Re: KVM induced panic on 2.6.38[2367] & 2.6.39

Brad Campbell
2011-06-08T00:18:10Z

On 08/06/11 06:57, Patrick McHardy wrote:
> On 07.06.2011 20:31, Eric Dumazet wrote:
>> Le mardi 07 juin 2011 à 17:35 +0200, Patrick McHardy a écrit :
>>
>>> The main suspects would be NAT and TCPMSS. Did you also try whether
>>> the crash occurs with only one of these these rules?
>>>
>>>> I've just compiled out CONFIG_BRIDGE_NETFILTER and can no longer access
>>>> the address the way I was doing it, so that's a no-go for me.
>>>
>>> That's really weird since you're apparently not using any bridge
>>> netfilter features. It shouldn't have any effect besides changing
>>> at which point ip_tables is invoked. How are your network devices
>>> configured (specifically any bridges)?
>>
>> Something in the kernel does
>>
>> u16 *ptr = addr (given by kmalloc())
>>
>> ptr[-1] = 0;
>>
>> Could be an off-one error in a memmove()/memcopy() or loop...
>>
>> I cant see a network issue here.
>
> So far me neither, but netfilter appears to trigger the bug.

Would it help if I tried some older kernels? This issue only surfaced
for me recently as I only installed the VM's in question about 12 weeks
ago and have only just started really using them in anger. I could try
reproducing it on progressively older kernels to see if I can find one
that works and then bisect from there.