In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: sdata can be NULL during AMPDU start ieee80211_tx_ba_session_handle_start() may get NULL for sdata when a deauthentication is ongoing. Here a trace triggering the race with the hostapd test multi_ap_fronthaul_on_ap: (gdb) list *drv_ampdu_action+0x46 0x8b16 is in drv_ampdu_action (net/mac80211/driver-ops.c:396). 391 int ret = -EOPNOTSUPP; 392 393 might_sleep(); 394 395 sdata = get_bss_sdata(sdata); 396 if (!check_sdata_in_driver(sdata)) 397 return -EIO; 398 399 trace_drv_ampdu_action(local, sdata, params); 400 wlan0: moving STA 02:00:00:00:03:00 to state 3 wlan0: associated wlan0: deauthenticating from 02:00:00:00:03:00 by local choice (Reason: 3=DEAUTH_LEAVING) wlan3.sta1: Open BA session requested for 02:00:00:00:00:00 tid 0 wlan3.sta1: dropped frame to 02:00:00:00:00:00 (unauthorized port) wlan0: moving STA 02:00:00:…