From 72d00b6e9a74534fb5e872eea6c46c77ec8e3746 Mon Sep 17 00:00:00 2001 From: Bhagavathi Perumal S Date: Tue, 16 Apr 2019 12:54:40 +0530 Subject: [PATCH] mac80211: Fix kernel panic due to use of txq after free MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit [ Upstream commit f1267cf3c01b12e0f843fb6a7450a7f0b2efab8a ] The txq of vif is added to active_txqs list for ATF TXQ scheduling in the function ieee80211_queue_skb(), but it was not properly removed before freeing the txq object. It was causing use after free of the txq objects from the active_txqs list, result was kernel panic due to invalid memory access. Fix kernel invalid memory access by properly removing txq object from active_txqs list before free the object. Signed-off-by: Bhagavathi Perumal S Acked-by: Toke Høiland-Jørgensen Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- net/mac80211/iface.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 5768560cbfc3..ad03331ee785 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1937,6 +1937,9 @@ void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata) list_del_rcu(&sdata->list); mutex_unlock(&sdata->local->iflist_mtx); + if (sdata->vif.txq) + ieee80211_txq_purge(sdata->local, to_txq_info(sdata->vif.txq)); + synchronize_rcu(); if (sdata->dev) { -- 2.20.1