diff options
| author | Martin Willi <martin@strongswan.org> | 2018-09-25 09:41:13 +0200 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2018-09-26 11:20:13 +0200 |
| commit | 628980e5c8f038f730582c6ee50b7410741cd96e (patch) | |
| tree | 76ffd6708bc16fa3e6a40436d4faa570180559fc /drivers/net/wireless/mac80211_hwsim.c | |
| parent | 30fe6d50eb088783c8729c7d930f65296b2b3fa7 (diff) | |
mac80211_hwsim: fix locking when iterating radios during ns exit
The cleanup of radios during namespace exit has recently been reworked
to directly delete a radio while temporarily releasing the spinlock,
fixing a race condition between the work-queue execution and namespace
exits. However, the temporary unlock allows unsafe modifications on the
iterated list, resulting in a potential crash when continuing the
iteration of additional radios.
Move radios about to destroy to a temporary list, and clean that up
after releasing the spinlock once iteration is complete.
Fixes: 8cfd36a0b53a ("mac80211_hwsim: fix use-after-free bug in hwsim_exit_net")
Signed-off-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'drivers/net/wireless/mac80211_hwsim.c')
| -rw-r--r-- | drivers/net/wireless/mac80211_hwsim.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 1068757ec42e..f1150d321875 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -3646,6 +3646,7 @@ static __net_init int hwsim_init_net(struct net *net) static void __net_exit hwsim_exit_net(struct net *net) { struct mac80211_hwsim_data *data, *tmp; + LIST_HEAD(list); spin_lock_bh(&hwsim_radio_lock); list_for_each_entry_safe(data, tmp, &hwsim_radios, list) { @@ -3656,17 +3657,19 @@ static void __net_exit hwsim_exit_net(struct net *net) if (data->netgroup == hwsim_net_get_netgroup(&init_net)) continue; - list_del(&data->list); + list_move(&data->list, &list); rhashtable_remove_fast(&hwsim_radios_rht, &data->rht, hwsim_rht_params); hwsim_radios_generation++; - spin_unlock_bh(&hwsim_radio_lock); + } + spin_unlock_bh(&hwsim_radio_lock); + + list_for_each_entry_safe(data, tmp, &list, list) { + list_del(&data->list); mac80211_hwsim_del_radio(data, wiphy_name(data->hw->wiphy), NULL); - spin_lock_bh(&hwsim_radio_lock); } - spin_unlock_bh(&hwsim_radio_lock); ida_simple_remove(&hwsim_netgroup_ida, hwsim_net_get_netgroup(net)); } |