From: Jouni Malinen <j@w1.fi>
Date: Thu, 26 May 2022 21:23:25 +0000 (+0300)
Subject: hs20-osu-client: Explicit checks for snprintf() result
X-Git-Tag: hostap_2_11~1870
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=02047e9c8858af7e5fc9f2684d272e65e264c078;p=thirdparty%2Fhostap.git

hs20-osu-client: Explicit checks for snprintf() result

Get rid of the gcc warnings on potentially truncating the output buffer
by explicitly checking that there was enough room to write the full
string.

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

diff --git a/hs20/client/osu_client.c b/hs20/client/osu_client.c
index 7b274dac9..01e7b7553 100644
--- a/hs20/client/osu_client.c
+++ b/hs20/client/osu_client.c
@@ -2018,6 +2018,7 @@ static struct osu_data * parse_osu_providers(const char *fname, size_t *count)
 	struct osu_data *osu = NULL, *last = NULL;
 	size_t osu_count = 0;
 	char *pos, *end;
+	int res;
 
 	f = fopen(fname, "r");
 	if (f == NULL) {
@@ -2037,15 +2038,20 @@ static struct osu_data * parse_osu_providers(const char *fname, size_t *count)
 			osu = last;
 			last = &osu[osu_count++];
 			memset(last, 0, sizeof(*last));
-			snprintf(last->bssid, sizeof(last->bssid), "%s",
-				 buf + 13);
+			res = os_snprintf(last->bssid, sizeof(last->bssid),
+					  "%s", buf + 13);
+			if (os_snprintf_error(sizeof(last->bssid), res))
+				break;
 			continue;
 		}
 		if (!last)
 			continue;
 
 		if (strncmp(buf, "uri=", 4) == 0) {
-			snprintf(last->url, sizeof(last->url), "%s", buf + 4);
+			res = os_snprintf(last->url, sizeof(last->url),
+					  "%s", buf + 4);
+			if (os_snprintf_error(sizeof(last->url), res))
+				break;
 			continue;
 		}
 
@@ -2055,26 +2061,37 @@ static struct osu_data * parse_osu_providers(const char *fname, size_t *count)
 		}
 
 		if (strncmp(buf, "osu_ssid=", 9) == 0) {
-			snprintf(last->osu_ssid, sizeof(last->osu_ssid),
-				 "%s", buf + 9);
+			res = os_snprintf(last->osu_ssid,
+					  sizeof(last->osu_ssid),
+					  "%s", buf + 9);
+			if (os_snprintf_error(sizeof(last->osu_ssid), res))
+				break;
 			continue;
 		}
 
 		if (strncmp(buf, "osu_ssid2=", 10) == 0) {
-			snprintf(last->osu_ssid2, sizeof(last->osu_ssid2),
-				 "%s", buf + 10);
+			res = os_snprintf(last->osu_ssid2,
+					  sizeof(last->osu_ssid2),
+					  "%s", buf + 10);
+			if (os_snprintf_error(sizeof(last->osu_ssid2), res))
+				break;
 			continue;
 		}
 
 		if (os_strncmp(buf, "osu_nai=", 8) == 0) {
-			os_snprintf(last->osu_nai, sizeof(last->osu_nai),
-				    "%s", buf + 8);
+			res = os_snprintf(last->osu_nai, sizeof(last->osu_nai),
+					  "%s", buf + 8);
+			if (os_snprintf_error(sizeof(last->osu_nai), res))
+				break;
 			continue;
 		}
 
 		if (os_strncmp(buf, "osu_nai2=", 9) == 0) {
-			os_snprintf(last->osu_nai2, sizeof(last->osu_nai2),
-				    "%s", buf + 9);
+			res = os_snprintf(last->osu_nai2,
+					  sizeof(last->osu_nai2),
+					  "%s", buf + 9);
+			if (os_snprintf_error(sizeof(last->osu_nai2), res))
+				break;
 			continue;
 		}
 
@@ -2087,8 +2104,14 @@ static struct osu_data * parse_osu_providers(const char *fname, size_t *count)
 				continue;
 			*pos++ = '\0';
 			txt = &last->friendly_name[last->friendly_name_count++];
-			snprintf(txt->lang, sizeof(txt->lang), "%s", buf + 14);
-			snprintf(txt->text, sizeof(txt->text), "%s", pos);
+			res = os_snprintf(txt->lang, sizeof(txt->lang),
+					  "%s", buf + 14);
+			if (os_snprintf_error(sizeof(txt->lang), res))
+				break;
+			res = os_snprintf(txt->text, sizeof(txt->text),
+					  "%s", pos);
+			if (os_snprintf_error(sizeof(txt->text), res))
+				break;
 		}
 
 		if (strncmp(buf, "desc=", 5) == 0) {
@@ -2100,8 +2123,14 @@ static struct osu_data * parse_osu_providers(const char *fname, size_t *count)
 				continue;
 			*pos++ = '\0';
 			txt = &last->serv_desc[last->serv_desc_count++];
-			snprintf(txt->lang, sizeof(txt->lang), "%s", buf + 5);
-			snprintf(txt->text, sizeof(txt->text), "%s", pos);
+			res = os_snprintf(txt->lang, sizeof(txt->lang),
+					  "%s", buf + 5);
+			if (os_snprintf_error(sizeof(txt->lang), res))
+				break;
+			res = os_snprintf(txt->text, sizeof(txt->text),
+					  "%s", pos);
+			if (os_snprintf_error(sizeof(txt->text), res))
+				break;
 		}
 
 		if (strncmp(buf, "icon=", 5) == 0) {
@@ -2124,23 +2153,30 @@ static struct osu_data * parse_osu_providers(const char *fname, size_t *count)
 			if (!end)
 				continue;
 			*end = '\0';
-			snprintf(icon->lang, sizeof(icon->lang), "%s", pos);
+			res = os_snprintf(icon->lang, sizeof(icon->lang),
+					  "%s", pos);
+			if (os_snprintf_error(sizeof(icon->lang), res))
+				break;
 			pos = end + 1;
 
 			end = strchr(pos, ':');
 			if (end)
 				*end = '\0';
-			snprintf(icon->mime_type, sizeof(icon->mime_type),
-				 "%s", pos);
-			if (!pos)
+			res = os_snprintf(icon->mime_type,
+					  sizeof(icon->mime_type), "%s", pos);
+			if (os_snprintf_error(sizeof(icon->mime_type), res))
+				break;
+			if (!end)
 				continue;
 			pos = end + 1;
 
 			end = strchr(pos, ':');
 			if (end)
 				*end = '\0';
-			snprintf(icon->filename, sizeof(icon->filename),
-				 "%s", pos);
+			res = os_snprintf(icon->filename,
+					  sizeof(icon->filename), "%s", pos);
+			if (os_snprintf_error(sizeof(icon->filename), res))
+				break;
 			continue;
 		}
 	}