[wpa_supplicant] Cherry-pick security fixes (April 29, 2019)

09ab81b9e WPA: Clear authenticator keys for a STA on deinit/disconnection
7958223fd EAP-pwd: Use const_time_memcmp() for pwd_value >= prime comparison
8e14b030e SAE: Use const_time_memcmp() for pwd_value >= prime comparison
c3805fb62 Ignore channel switch event if AP interface is not yet ready
eb314e8af Verify that channel info is available in hostapd_hw_get_channel()
b9058266f Clear cached extended_capa pointers on hapd_deinit() call

Bug: 129344244
Test: Connect to SAE network
Test: Connect to EAP network
Test: Enable/disable SoftAP
Test: Regression test (Bug: 131703857)
Change-Id: Iac0d8a7972b905da0d0f0f7414f1eea910b8986b
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);