From: Jouni Malinen <j@w1.fi>
Date: Mon, 25 Feb 2019 00:57:41 +0000 (+0200)
Subject: UBSan: Avoid a warning on unsigned integer overflow
X-Git-Tag: hostap_2_8~313
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2f7bc0681632e153dd69ed651f91941b4ed3ade3;p=thirdparty%2Fhostap.git

UBSan: Avoid a warning on unsigned integer overflow

wpa_non_pref_chan_cmp() needs to use explicit typecasts to avoid UBSan
warnings for unsigned integer overflows.

mbo.c:298:26: runtime error: unsigned integer overflow: 1 - 2 cannot be represented in type 'unsigned int'

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

diff --git a/wpa_supplicant/mbo.c b/wpa_supplicant/mbo.c
index bd5020a80..d2f145114 100644
--- a/wpa_supplicant/mbo.c
+++ b/wpa_supplicant/mbo.c
@@ -293,10 +293,10 @@ static int wpa_non_pref_chan_cmp(const void *_a, const void *_b)
 	const struct wpa_mbo_non_pref_channel *a = _a, *b = _b;
 
 	if (a->oper_class != b->oper_class)
-		return a->oper_class - b->oper_class;
+		return (int) a->oper_class - (int) b->oper_class;
 	if (a->reason != b->reason)
-		return a->reason - b->reason;
-	return a->preference - b->preference;
+		return (int) a->reason - (int) b->reason;
+	return (int) a->preference - (int) b->preference;
 }