From: Felix Fietkau <nbd@nbd.name>
Date: Thu, 8 Jul 2021 16:33:03 +0200
Subject: [PATCH] hostapd: fix use of uninitialized stack variables

When a CSA is performed on an 80 MHz channel, hostapd_change_config_freq
unconditionally calls hostapd_set_oper_centr_freq_seg0/1_idx with seg0/1
filled by ieee80211_freq_to_chan.
However, if ieee80211_freq_to_chan fails (because the freq is 0 or invalid),
seg0/1 remains uninitialized and filled with stack garbage, causing errors
such as "hostapd: 80 MHz: center segment 1 configured"

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

--- a/src/ap/hostapd.c
+++ b/src/ap/hostapd.c
@@ -3453,7 +3453,7 @@ static int hostapd_change_config_freq(st
 				      struct hostapd_freq_params *old_params)
 {
 	int channel;
-	u8 seg0, seg1;
+	u8 seg0 = 0, seg1 = 0;
 	struct hostapd_hw_modes *mode;
 
 	if (!params->channel) {