Subject: Re: 3.9.5+: Crash in tcp_input.c:4810.

From: Ben Greear <[email-masked]>
Date: Tue, 02 Jul 2013 21:49:42 -0700

On 07/02/2013 09:41 PM, Eric Dumazet wrote:
> On Tue, 2013-07-02 at 20:21 -0700, Ben Greear wrote:
>
>> What kinds of things could a driver do to cause this.  Maybe modify an
>> skb after it has sent it up the stack, or something like that?
>>
>
> It might be a genuine TCP bug, who knows...
>
>
>> We haven't been able to reproduce on a clean 3.10 yet...but it often takes days,
>> so we'll leave the test up through end of this week if we don't hit it
>> sooner...
>
> TCP collapse is/should be really rare, but losses can of course trigger
> it.

Well, network emulators are easy to come by in the office....  Maybe running
a bunch of TCP connections through a lossy network would exercise this code
path a bit?  Aside from random pkt loss, any other types of network conditions
that might help trigger this faster?

I'll set up some tests using some wired ethernet...if we can trigger it there
then we at least know it doesn't depend on ath9k...

Thanks,
Ben

-- 
Ben Greear <[email-masked]>
Candela Technologies Inc  http://www.candelatech.com