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. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
