diff --git a/src/ap/drv_callbacks.c b/src/ap/drv_callbacks.c
index 8ddf754..952a3d5 100644
--- a/src/ap/drv_callbacks.c
+++ b/src/ap/drv_callbacks.c
@@ -787,6 +787,13 @@
 		       freq, ht, hapd->iconf->ch_switch_vht_config, offset,
 		       width, channel_width_to_string(width), cf1, cf2);
 
+	if (!hapd->iface->current_mode) {
+		hostapd_logger(hapd, NULL, HOSTAPD_MODULE_IEEE80211,
+			       HOSTAPD_LEVEL_WARNING,
+			       "ignore channel switch since the interface is not yet ready");
+		return;
+	}
+
 	hapd->iface->freq = freq;
 
 	channel = hostapd_hw_get_channel(hapd, freq);
diff --git a/src/ap/hostapd.c b/src/ap/hostapd.c
index 20c8e8f..0bd6892 100644
--- a/src/ap/hostapd.c
+++ b/src/ap/hostapd.c
@@ -2486,8 +2486,12 @@
 			wpa_printf(MSG_DEBUG, "%s:bss[%d]->drv_priv=%p",
 				   __func__, (int) j,
 				   hapd_iface->bss[j]->drv_priv);
-			if (hapd_iface->bss[j]->drv_priv == drv_priv)
+			if (hapd_iface->bss[j]->drv_priv == drv_priv) {
 				hapd_iface->bss[j]->drv_priv = NULL;
+				hapd_iface->extended_capa = NULL;
+				hapd_iface->extended_capa_mask = NULL;
+				hapd_iface->extended_capa_len = 0;
+			}
 		}
 	}
 }
diff --git a/src/ap/hw_features.c b/src/ap/hw_features.c
index 9d3d990..8ac33bb 100644
--- a/src/ap/hw_features.c
+++ b/src/ap/hw_features.c
@@ -936,11 +936,16 @@
 	int i, channel;
 	struct hostapd_hw_modes *mode;
 
-	channel = hw_get_chan(hapd->iface->current_mode, freq);
-	if (channel)
-		return channel;
+	if (hapd->iface->current_mode) {
+		channel = hw_get_chan(hapd->iface->current_mode, freq);
+		if (channel)
+			return channel;
+	}
+
 	/* Check other available modes since the channel list for the current
 	 * mode did not include the specified frequency. */
+	if (!hapd->iface->hw_features)
+		return 0;
 	for (i = 0; i < hapd->iface->num_hw_features; i++) {
 		mode = &hapd->iface->hw_features[i];
 		channel = hw_get_chan(mode, freq);
diff --git a/src/ap/wpa_auth.c b/src/ap/wpa_auth.c
index 616b205..e89a716 100644
--- a/src/ap/wpa_auth.c
+++ b/src/ap/wpa_auth.c
@@ -699,7 +699,7 @@
 #ifdef CONFIG_DPP2
 	wpabuf_clear_free(sm->dpp_z);
 #endif /* CONFIG_DPP2 */
-	os_free(sm);
+	bin_clear_free(sm, sizeof(*sm));
 }
 
 
@@ -1730,6 +1730,12 @@
 	case WPA_DEAUTH:
 	case WPA_DISASSOC:
 		sm->DeauthenticationRequest = TRUE;
+#ifdef CONFIG_IEEE80211R_AP
+		os_memset(sm->PMK, 0, sizeof(sm->PMK));
+		sm->pmk_len = 0;
+		os_memset(sm->xxkey, 0, sizeof(sm->xxkey));
+		sm->xxkey_len = 0;
+#endif /* CONFIG_IEEE80211R_AP */
 		break;
 	case WPA_REAUTH:
 	case WPA_REAUTH_EAPOL: