From 77cfaf52eca5cac30ed029507e0cab065f888995 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Toke=20H=C3=B8iland-J=C3=B8rgensen?= Date: Mon, 13 Aug 2018 14:16:25 +0200 Subject: [PATCH] mac80211: Run TXQ teardown code before de-registering interfaces MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The TXQ teardown code can reference the vif data structures that are stored in the netdev private memory area if there are still packets on the queue when it is being freed. Since the TXQ teardown code is run after the netdevs are freed, this can lead to a use-after-free. Fix this by moving the TXQ teardown code to earlier in ieee80211_unregister_hw(). Reported-by: Ben Greear Tested-by: Ben Greear Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: Johannes Berg --- net/mac80211/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/mac80211/main.c b/net/mac80211/main.c index fb73451ed85e..0358f20b675f 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -1182,6 +1182,7 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw) #if IS_ENABLED(CONFIG_IPV6) unregister_inet6addr_notifier(&local->ifa6_notifier); #endif + ieee80211_txq_teardown_flows(local); rtnl_lock(); @@ -1210,7 +1211,6 @@ void ieee80211_unregister_hw(struct ieee80211_hw *hw) skb_queue_purge(&local->skb_queue); skb_queue_purge(&local->skb_queue_unreliable); skb_queue_purge(&local->skb_queue_tdls_chsw); - ieee80211_txq_teardown_flows(local); destroy_workqueue(local->workqueue); wiphy_unregister(local->hw.wiphy);