From: Johannes Berg Date: Fri, 22 Jan 2021 16:11:16 +0000 (+0100) Subject: mac80211: pause TX while changing interface type X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=054c9939b4800a91475d8d89905827bf9e1ad97a;p=linux.git mac80211: pause TX while changing interface type 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.I6997841933c17b093535c31d29355be3c0c39628@changeid Signed-off-by: Johannes Berg --- diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 8bf9c0e974d62..8e281c2e644d5 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1078,6 +1078,7 @@ 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 3b9ec4ef81c3b..b31417f40bd56 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -1617,6 +1617,10 @@ 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); @@ -1639,6 +1643,8 @@ 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; }