iwlwifi: mvm: responder: allow to set only the HLTK for an associated station

For secure ranging with an associated station, the driver only needs
to set the HLTK. There is no need to add an internal station for PMF
since the FW will use the existing station which already has the TK
installed.
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200930161256.fcebaa5c9bc8.Ic584cc47fee717d0bdb43965798dbdf45d89910a@changeidSigned-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/mvm/ftm-responder.c

@@ -322,7 +322,7 @@ int iwl_mvm_ftm_respoder_add_pasn_sta(struct iwl_mvm *mvm,
 				      u8 *hltk, u32 hltk_len)
 {
 	int ret;
-	struct iwl_mvm_pasn_sta *sta;
+	struct iwl_mvm_pasn_sta *sta = NULL;
 	struct iwl_mvm_pasn_hltk_data hltk_data = {
 		.addr = addr,
 		.hltk = hltk,
@@ -343,20 +343,23 @@ int iwl_mvm_ftm_respoder_add_pasn_sta(struct iwl_mvm *mvm,
 		return -EINVAL;
 	}
 
-	sta = kmalloc(sizeof(*sta), GFP_KERNEL);
-	if (!sta)
-		return -ENOBUFS;
+	if (tk && tk_len) {
+		sta = kzalloc(sizeof(*sta), GFP_KERNEL);
+		if (!sta)
+			return -ENOBUFS;
 
-	ret = iwl_mvm_add_pasn_sta(mvm, vif, &sta->int_sta, addr, cipher, tk,
-				   tk_len);
-	if (ret) {
-		kfree(sta);
-		return ret;
+		ret = iwl_mvm_add_pasn_sta(mvm, vif, &sta->int_sta, addr,
+					   cipher, tk, tk_len);
+		if (ret) {
+			kfree(sta);
+			return ret;
+		}
 	}
 
 	ret = iwl_mvm_ftm_responder_dyn_cfg_v3(mvm, vif, NULL, &hltk_data);
 	if (ret) {
-		iwl_mvm_resp_del_pasn_sta(mvm, vif, sta);
+		if (sta)
+			iwl_mvm_resp_del_pasn_sta(mvm, vif, sta);
 		return ret;
 	}