4.18-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 628980e5c8f038f730582c6ee50b7410741cd96e ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireless/mac80211_hwsim.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 80e2c8595c7c..6b90bef58293 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -3523,6 +3523,7 @@ 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) { @@ -3533,17 +3534,19 @@ 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)); }