wifi: rtw88: use work to update rate to avoid RCU warning

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: wifi: rtw88: use work to update rate to avoid RCU warning The ieee80211_ops::sta_rc_update must be atomic, because ieee80211_chan_bw_change() holds rcu_read lock while calling drv_sta_rc_update(), so create a work to do original things. Voluntary context switch within RCU read-side critical section! WARNING: CPU: 0 PID: 4621 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x571/0x5d0 CPU: 0 PID: 4621 Comm: kworker/u16:2 Tainted: G W OE Workqueue: phy3 ieee80211_chswitch_work [mac80211] RIP: 0010:rcu_note_context_switch+0x571/0x5d0 Call Trace: <TASK> __schedule+0xb0/0x1460 ? __mod_timer+0x116/0x360 schedule+0x5a/0xc0 schedule_timeout+0x87/0x150 ? trace_raw_output_tick_stop+0x60/0x60 wait_for_completion_timeout+0x7b/0x140 usb_start_wait_urb+0x82/0x160 [usbcore usb_control_msg+0xe3/0x140 [usbcore rtw_usb_read+0x88/0xe0 [rtw_usb rtw_usb_read8+0xf/0x10 [rtw_usb rtw_fw_send_h2c_command+0xa0/0x170 [rtw_core rtw_fw_send_ra_info+0xc9/0xf0 [rtw_core drv_sta_rc_update+0x7c/0x160 [mac80211 ieee80211_chan_bw_change+0xfb/0x110 [mac80211 ieee80211_change_chanctx+0x38/0x130 [mac80211 ieee80211_vif_use_reserved_switch+0x34e/0x900 [mac80211 ieee80211_link_use_reserved_context+0x88/0xe0 [mac80211 ieee80211_chswitch_work+0x95/0x170 [mac80211 process_one_work+0x201/0x410 worker_thread+0x4a/0x3b0 ? process_one_work+0x410/0x410 kthread+0xe1/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 </TASK>

References

• https://git.kernel.org/stable/c/107677a8f43521e33e4a653e50fdf55ba622a4ce
• https://git.kernel.org/stable/c/dd3af22323e79a2ffabed366db20aab83716fe6f
• https://git.kernel.org/stable/c/bcafcb959a57a6890e900199690c5fc47da1a304