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: 34d4bc4d41 ("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 <johannes.berg@intel.com>
This commit is contained in:
Johannes Berg 2021-01-22 17:11:16 +01:00
Родитель 5122565188
Коммит 054c9939b4
2 изменённых файлов: 7 добавлений и 0 удалений

Просмотреть файл

@ -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,
};

Просмотреть файл

@ -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;
}