From: Johannes Berg johannes.berg@intel.com
[ Upstream commit 054c9939b4800a91475d8d89905827bf9e1ad97a ]
syzbot reported a crash that happened when changing the interface type around a lot, and while it might have been easy to fix just the symptom there, a little deeper investigation found that really the reason is that we allowed packets to be transmitted while in the middle of changing the interface type.
Disallow TX by stopping the queues while changing the type.
Fixes: 34d4bc4d41d2 ("mac80211: support runtime interface type changes") Reported-by: syzbot+d7a3b15976bf7de2238a@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20210122171115.b321f98f4d4f.I6997841933c17b093535c... Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/mac80211/ieee80211_i.h | 1 + net/mac80211/iface.c | 6 ++++++ 2 files changed, 7 insertions(+)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 0e209a88d88a7..651705565dfb9 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1047,6 +1047,7 @@ enum queue_stop_reason { IEEE80211_QUEUE_STOP_REASON_FLUSH, IEEE80211_QUEUE_STOP_REASON_TDLS_TEARDOWN, IEEE80211_QUEUE_STOP_REASON_RESERVE_TID, + IEEE80211_QUEUE_STOP_REASON_IFTYPE_CHANGE,
IEEE80211_QUEUE_STOP_REASONS, }; diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index 6ce13e976b7a2..dc398a1816788 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1559,6 +1559,10 @@ static int ieee80211_runtime_change_iftype(struct ieee80211_sub_if_data *sdata, if (ret) return ret;
+ ieee80211_stop_vif_queues(local, sdata, + IEEE80211_QUEUE_STOP_REASON_IFTYPE_CHANGE); + synchronize_net(); + ieee80211_do_stop(sdata, false);
ieee80211_teardown_sdata(sdata); @@ -1579,6 +1583,8 @@ static int ieee80211_runtime_change_iftype(struct ieee80211_sub_if_data *sdata, err = ieee80211_do_open(&sdata->wdev, false); WARN(err, "type change: do_open returned %d", err);
+ ieee80211_wake_vif_queues(local, sdata, + IEEE80211_QUEUE_STOP_REASON_IFTYPE_CHANGE); return ret; }