From: Jouni Malinen <j@w1.fi>
Date: Sat, 23 Feb 2019 16:14:29 +0000 (+0200)
Subject: UBSan: Split loop index decrementation into a separate step
X-Git-Tag: hostap_2_8~317
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b3957edbe9c646129481b606ccf653101ba7bc15;p=thirdparty%2Fhostap.git

UBSan: Split loop index decrementation into a separate step

Avoid an unnecessary unsigned integer overflow warning due to loop index
j-- use.

hostapd.c:661:10: runtime error: unsigned integer overflow: 0 - 1 cannot be represented in type 'unsigned int'

Signed-off-by: Jouni Malinen <j@w1.fi>
---

diff --git a/src/ap/hostapd.c b/src/ap/hostapd.c
index 5dcec47e1..60943cd02 100644
--- a/src/ap/hostapd.c
+++ b/src/ap/hostapd.c
@@ -658,8 +658,10 @@ static int hostapd_validate_bssid_configuration(struct hostapd_iface *iface)
 	for (i = 5; i > 5 - j; i--)
 		mask[i] = 0;
 	j = bits % 8;
-	while (j--)
+	while (j) {
+		j--;
 		mask[i] <<= 1;
+	}
 
 skip_mask_ext:
 	wpa_printf(MSG_DEBUG, "BSS count %lu, BSSID mask " MACSTR " (%d bits)",