Re: p54usb kernel panic on recent mainline kernels

[Larry Finger <Larry.Finger@lwfinger.net>]

On 12/26/2014 08:35 AM, Christian Lamparter wrote:
> On Friday, December 26, 2014 04:23:21 AM Christopher Chavez wrote:
>> Larry Finger <Larry.Finger@...> writes:
>>> In any case, file a bug report at bugzilla.kernel.org, mark it as a regression,
>>> and post the bug number here. If you are able to finish the bisection, that
>>> would be helpful.
>>
>> Reported.
>> https://bugzilla.kernel.org/show_bug.cgi?id=90331
>
> According to what Larry wrote, this bug should disappear, if
> the hw crypto offloading is disabled.
>
> Christopher, can you please load the p54common kernel module
> with the module parameter "nohwcrypt=1" and report back?

Christian,

I can confirm that the skb panic goes away if hardware encryption is disabled.

My bisection led to a branch commit d17ec4d as the "bad" commit. Rather than 
finding out where the bisection went bad, I added code to check skb->tail, 
skb->end, and the length to be added. At the time of the call that panics, there 
are 6 bytes between tail and end with 8 bytes needed.

I will be looking for the place where the driver calculates how large the skb 
should be.

Larry