wifi: mac80211_hwsim: Limit destroy_on_close radio removal to netgroup

hwsim radios marked destroy_on_close are removed when the Netlink socket
that created them is closed. As the portid is not unique across network
namespaces, closing a socket in one namespace may remove radios in another
if it has the destroy_on_close flag set.

Instead of matching the network namespace, match the netgroup of the radio
to limit radio removal to those that have been created by the closing
Netlink socket. The netgroup of a radio identifies the network namespace
it was created in, and matching on it removes a destroy_on_close radio
even if it has been moved to another namespace.

Fixes: 100cb9f ("mac80211_hwsim: Allow managing radios from non-initial namespaces")
Signed-off-by: Martin Willi <martin@strongswan.org>
Link: https://patch.msgid.link/20251103082436.30483-1-martin@strongswan.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Author: martinwilli

drivers/net/wireless/virtual/mac80211_hwsim.c

@@ -6698,14 +6698,15 @@ static struct genl_family hwsim_genl_family __ro_after_init = {
 	.n_mcgrps = ARRAY_SIZE(hwsim_mcgrps),
 };
 
-static void remove_user_radios(u32 portid)
+static void remove_user_radios(u32 portid, int netgroup)
 {
 	struct mac80211_hwsim_data *entry, *tmp;
 	LIST_HEAD(list);
 
 	spin_lock_bh(&hwsim_radio_lock);
 	list_for_each_entry_safe(entry, tmp, &hwsim_radios, list) {
-		if (entry->destroy_on_close && entry->portid == portid) {
+		if (entry->destroy_on_close && entry->portid == portid &&
+		    entry->netgroup == netgroup) {
 			list_move(&entry->list, &list);
 			rhashtable_remove_fast(&hwsim_radios_rht, &entry->rht,
 					       hwsim_rht_params);
@@ -6730,7 +6731,7 @@ static int mac80211_hwsim_netlink_notify(struct notifier_block *nb,
 	if (state != NETLINK_URELEASE)
 		return NOTIFY_DONE;
 
-	remove_user_radios(notify->portid);
+	remove_user_radios(notify->portid, hwsim_net_get_netgroup(notify->net));
 
 	if (notify->portid == hwsim_net_get_wmediumd(notify->net)) {
 		printk(KERN_INFO "mac80211_hwsim: wmediumd released netlink"