Re: Kernel crash on startup - bisected to commit 3b24d854cb35

[Kalle Valo]

Larry Finger <Larry.Finger@xxxxxxxxxxxx> writes:

>> Can you double check you have this fix ?
>>
>> commit 8501786929de4616b10b8059ad97abd304a7dddf
>> Author: Eric Dumazet <edumazet@xxxxxxxxxx>
>> Date:   Wed Apr 6 22:07:34 2016 -0700
>>
>>      tcp/dccp: fix inet_reuseport_add_sock()
>>
>>      David Ahern reported panics in __inet_hash() caused by my recent commit.
>>
>>      The reason is inet_reuseport_add_sock() was still using
>>      sk_nulls_for_each_rcu() instead of sk_for_each_rcu().
>>      SO_REUSEPORT enabled listeners were causing an instant crash.
>>
>>      While chasing this bug, I found that I forgot to clear SOCK_RCU_FREE
>>      flag, as it is inherited from the parent at clone time.
>>
>>      Fixes: 3b24d854cb35 ("tcp/dccp: do not touch listener sk_refcnt
>> under synflood")
>>      Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
>>      Reported-by: David Ahern <dsa@xxxxxxxxxxxxxxxxxxx>
>>      Tested-by: David Ahern <dsa@xxxxxxxxxxxxxxxxxxx>
>>      Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
>
> No, I did not have that patch. After pulling from net-next to get it,
> my system no longer panics.
>
> Note to linux-wireless readers. At the moment, a system built from
> wireless-drivers-next will have this problem.

I'm currently writing a pull request to Dave and once he pulls it I'll
fast forward wireless-drivers-next to latest net-next. Usually this take
two days or so.

-- 
Kalle Valo