From a50e5fb8db83c5b57392204c21ea6c5c4ccefde6 Mon Sep 17 00:00:00 2001 From: Sara Sharon Date: Sat, 15 Dec 2018 11:03:10 +0200 Subject: [PATCH 1/3] mac80211: fix a kernel panic when TXing after TXQ teardown Recently TXQ teardown was moved earlier in ieee80211_unregister_hw(), to avoid a use-after-free of the netdev data. However, interfaces aren't fully removed at the point, and cfg80211_shutdown_all_interfaces can for example, TX a deauth frame. Move the TXQ teardown to the point between cfg80211_shutdown_all_interfaces and the free of netdev queues, so we can be sure they are torn down before netdev is freed, but after there is no ongoing TX. Fixes: 77cfaf52eca5 ("mac80211: Run TXQ teardown code before de-registering interfaces") Signed-off-by: Sara Sharon Signed-off-by: Luca Coelho Signed-off-by: Johannes Berg --- net/mac80211/iface.c | 3 +++ net/mac80211/main.c | 2 -- 2 files changed, 3 insertions(+), 2 deletions(-) --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -7,6 +7,7 @@ * Copyright 2008, Johannes Berg * Copyright 2013-2014 Intel Mobile Communications GmbH * Copyright (c) 2016 Intel Deutschland GmbH + * Copyright (C) 2018 Intel Corporation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -2035,6 +2036,8 @@ void ieee80211_remove_interfaces(struct WARN(local->open_count, "%s: open count remains %d\n", wiphy_name(local->hw.wiphy), local->open_count); + ieee80211_txq_teardown_flows(local); + mutex_lock(&local->iflist_mtx); list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) { list_del(&sdata->list); --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -1200,7 +1200,6 @@ int ieee80211_register_hw(struct ieee802 rtnl_unlock(); ieee80211_led_exit(local); ieee80211_wep_free(local); - ieee80211_txq_teardown_flows(local); fail_flows: destroy_workqueue(local->workqueue); fail_workqueue: @@ -1226,7 +1225,6 @@ void ieee80211_unregister_hw(struct ieee #if IS_ENABLED(__disabled__CONFIG_IPV6) unregister_inet6addr_notifier(&local->ifa6_notifier); #endif - ieee80211_txq_teardown_flows(local); rtnl_lock();