adc539784c
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. Link: https://lore.kernel.org/linux-wireless/CA+shoWQ7P49jhQasofDcTdQhiuarPTjYEDa--NiVVx494WcuQw@mail.gmail.com/ Signed-off-by: Marcin Ślusarz <mslusarz@renau.com> Cc: Tim K <tpkuester@gmail.com> Cc: Ping-Ke Shih <pkshih@realtek.com> Cc: Larry Finger <Larry.Finger@lwfinger.net> Cc: Kalle Valo <kvalo@kernel.org> Cc: linux-wireless@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ping-Ke Shih <pkshih@realtek.com> Link: https://patch.msgid.link/20240528110246.477321-1-marcin.slusarz@gmail.com
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.