Re: rtlwifi NULL pointer dereference

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

On 06/06/2015 08:20 AM, Kalle Valo wrote:
> Severn <severn@xephris.net> writes:
>
>> I've been hitting this NULL pointer deref with an rtl8188ee PCIE card.
>> It happens 100% of the time when I bring up a WPA2-PSK AP with hostapd
>> 2.4.
>>
>> If I revert 33511b157bbcebaef853cc1811992b664a2e5862, everything seems
>> to work properly.
>>
>> Below is my hostapd.conf and the crash log. This is mainline 4.0.4
>> with no patches.
>
> Below is the changelog for the commit. Larry & Taehee, what should we
> do?
>
> commit 33511b157bbcebaef853cc1811992b664a2e5862
> Author: Taehee Yoo <ap420073@gmail.com>
> Date:   Wed Jan 21 16:58:19 2015 +0900
>
>      rtlwifi: add support to send beacon frame.
>
>      In AP mode, beacon frame is necessary to keep connection.
>      this patch adds a sending beacon frame routine in initialization routine.
>
>      Signed-off-by: Taehee Yoo <ap420073@gmail.com>
>      Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
>      Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Kalle,

I'm trying to find the missing setup step when the new interface is added to the 
driver. Whatever it is is causing mac80211 to issue the warning at 
net/mac80211/driver-ops.h:12. That problem appears to cascade to the NULL 
pointer dereference. Any help would be appreciated.

Reversion of the above commit may be necessary, but I would like to see if we 
can get a better "fix" as that commit is necessary for proper beaconing.

Larry