RE: [PATCH] wifi: rtw88: schedule rx work after everything is set up

[Ping-Ke Shih]

Kalle Valo <kvalo@xxxxxxxxxx> wrote:
> marcin.slusarz@xxxxxxxxx writes:
> 
> > From: Marcin Ślusarz <mslusarz@xxxxxxxxx>
> >
> > Right now it's possible to hit NULL pointer dereference in
> > rtw_rx_fill_rx_status on hw object and/or its fields because
> > initialization routine can start getting USB replies before
> > rtw_dev is fully setup.
> >
> > The stack trace looks like this:
> >
> > rtw_rx_fill_rx_status
> > rtw8821c_query_rx_desc
> > rtw_usb_rx_handler
> > ...
> > queue_work
> > rtw_usb_read_port_complete
> > ...
> > usb_submit_urb
> > rtw_usb_rx_resubmit
> > rtw_usb_init_rx
> > rtw_usb_probe
> >
> > So while we do the async stuff rtw_usb_probe continues and calls
> > rtw_register_hw, which does all kinds of initialization (e.g.
> > via ieee80211_register_hw) that rtw_rx_fill_rx_status relies on.
> >
> > Fix this by moving the first usb_submit_urb after everything
> > is set up.
> >
> > For me, this bug manifested as:
> > [    8.893177] rtw_8821cu 1-1:1.2: band wrong, packet dropped
> > [    8.910904] rtw_8821cu 1-1:1.2: hw->conf.chandef.chan NULL in rtw_rx_fill_rx_status
> > because I'm using Larry's backport of rtw88 driver with the NULL
> > checks in rtw_rx_fill_rx_status.
> >
> > This should fix:
> > https://marc.info/?l=linux-wireless&m=167907688311943&w=2
> 
> Please use permalinks from lore.kernel.org, marc links don't contain the
> Message-Id and are hence unreliable.
> 

Use tags below: 

Reported-by: Tim K <tpkuester@xxxxxxxxx>
Closes: https://lore.kernel.org/linux-wireless/CA+shoWQ7P49jhQasofDcTdQhiuarPTjYEDa--NiVVx494WcuQw@xxxxxxxxxxxxxx/