Re: BUG: 4.10 rtlwifi regression - NULL pointer dereference

[Larry Finger]

On 01/08/2017 07:41 PM, lkml@xxxxxxxxxxx wrote:
> Hello list,
>
> Gave 4.10-rc2 a shot today using the attached config.  The kernel panics
> with a NULL pointer dereference upon starting dhclient after
> wpa_supplicant.
>
> The network device is a USB dongle:
> Bus 002 Device 002: ID 7392:7811 Edimax Technology Co., Ltd EW-7811Un 802.11n Wireless Adapter [Realtek RTL8188CUS]
>
> Reverting 'ba9f93f rtlwifi: Fix enter/exit power_save' prevents the
> crash.
>
> Sorry I don't have a verbatim capture of the panic, but I was able to
> catch the relevant parts and rtl_lps_leave() is dereferencing a NULL hw,
> below setup_arp_tx() and rtl_is_special_data().  That's what led me to
> reverting ba9f93f since it clearly plays with that stuff.
>
> FWIW machine is a plain X61s thinkpad, 1.8Ghz.

You need the patch from 
http://marc.info/?l=linux-wireless&m=148234081512703&w=2. It was pushed with the 
notation that it needed to be included in 4.10; however, it has not yet 
percolated through the system.

Larry