wifi: cfg80211: validate AP phy operation before starting it

Many regulatories can have HE/EHT Operation as not permitted. In such
cases, AP should not be allowed to start if it is using a channel
having the no operation flag set. However, currently there is no such
check in place.

Fix this issue by validating such IEs sent during start AP against the
channel flags.

Signed-off-by: Aditya Kumar Singh <[email protected]>
Reviewed-by: Jeff Johnson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Johannes Berg <[email protected]>

Author: Aditya Kumar Singh

net/wireless/nl80211.c

@@ -5909,6 +5909,21 @@ static void nl80211_send_ap_started(struct wireless_dev *wdev,
 	nlmsg_free(msg);
 }
 
+static int nl80211_validate_ap_phy_operation(struct cfg80211_ap_settings *params)
+{
+	struct ieee80211_channel *channel = params->chandef.chan;
+
+	if ((params->he_cap ||  params->he_oper) &&
+	    (channel->flags & IEEE80211_CHAN_NO_HE))
+		return -EOPNOTSUPP;
+
+	if ((params->eht_cap || params->eht_oper) &&
+	    (channel->flags & IEEE80211_CHAN_NO_EHT))
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
 static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 {
 	struct cfg80211_registered_device *rdev = info->user_ptr[0];
@@ -6178,6 +6193,10 @@ static int nl80211_start_ap(struct sk_buff *skb, struct genl_info *info)
 	if (err)
 		goto out_unlock;
 
+	err = nl80211_validate_ap_phy_operation(params);
+	if (err)
+		goto out_unlock;
+
 	if (info->attrs[NL80211_ATTR_AP_SETTINGS_FLAGS])
 		params->flags = nla_get_u32(
 			info->attrs[NL80211_ATTR_AP_SETTINGS_FLAGS]);