From: Johannes Berg When the first interface comes up, the radio LED is turned on. This can start the TPT trigger timer, which continues running. But if bringing up the interface fails then the timer keeps running and won't be stopped by anything, eventually it can be freed: ODEBUG: free active (active state 0) object: ffff888127e12130 object type: timer_list hint: tpt_trig_timer+0x0/0x300 net/mac80211/led.c:145 WARNING: CPU: 0 PID: 5923 at lib/debugobjects.c:612 debug_print_object+0x1a2/0x2b0 debug_check_no_obj_freed+0x4b7/0x600 lib/debugobjects.c:1129 kfree+0x436/0x670 mm/slub.c:6818 ieee80211_led_exit+0x162/0x1c0 net/mac80211/led.c:210 ieee80211_unregister_hw+0x27e/0x3a0 net/mac80211/main.c:1706 rt2x00lib_remove_dev+0x55b/0x670 Undo the LED state in the error path. Assisted-by: LLM Fixes: 67408c8c7b9d ("mac80211: selective throughput LED trigger active") Reported-by: syzbot+e84ecca6d1fa09a9b3d9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=e84ecca6d1fa09a9b3d9 Signed-off-by: Johannes Berg --- net/mac80211/iface.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 8c300e045fdf..4c34c3287eb4 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1606,8 +1606,12 @@ int ieee80211_do_open(struct wireless_dev *wdev, bool coming_up) err_del_interface: drv_remove_interface(local, sdata); err_stop: - if (!local->open_count) + if (!local->open_count) { + ieee80211_led_radio(local, false); + ieee80211_mod_tpt_led_trig(local, 0, + IEEE80211_TPT_LEDTRIG_FL_RADIO); drv_stop(local, false); + } if (sdata->vif.type == NL80211_IFTYPE_NAN_DATA) RCU_INIT_POINTER(sdata->u.nan_data.nmi, NULL); if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) -- 2.55.0