commit 8cfd36a0b53aeb4ec21d81eb79706697b84dfc3d upstream.

When destroying a net namespace, all hwsim interfaces, which are not created in default namespace are deleted. But the async deletion of the interfaces could last longer than the actual destruction of the namespace, which results to an use after free bug. Therefore use synchronous deletion in this case.

Fixes: 100cb9ff40e0 ("mac80211_hwsim: Allow managing radios from non-initial namespaces") Reported-by: syzbot+70ce058e01259de7bb1d@syzkaller.appspotmail.com Signed-off-by: Benjamin Beichler benjamin.beichler@uni-rostock.de Signed-off-by: Johannes Berg johannes.berg@intel.com --- This patch is prepared for linux-4.16.y branch

drivers/net/wireless/mac80211_hwsim.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 35b21f8152bb..20af54378cc0 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -3484,8 +3484,11 @@ static void __net_exit hwsim_exit_net(struct net *net) list_del(&data->list); rhashtable_remove_fast(&hwsim_radios_rht, &data->rht, hwsim_rht_params); - INIT_WORK(&data->destroy_work, destroy_radio); - queue_work(hwsim_wq, &data->destroy_work); + spin_unlock_bh(&hwsim_radio_lock); + mac80211_hwsim_del_radio(data, + wiphy_name(data->hw->wiphy), + NULL); + spin_lock_bh(&hwsim_radio_lock); } spin_unlock_bh(&hwsim_radio_lock); }