diff --git a/wpa_supplicant/config.c b/wpa_supplicant/config.c
index 786d26856..bd80b297b 100644
--- a/wpa_supplicant/config.c
+++ b/wpa_supplicant/config.c
@@ -358,9 +358,15 @@ static char * wpa_config_write_psk(const struct parse_data *data,
 	if (ssid->ext_psk) {
 		size_t len = 4 + os_strlen(ssid->ext_psk) + 1;
 		char *buf = os_malloc(len);
+		int res;
+
 		if (buf == NULL)
 			return NULL;
-		os_snprintf(buf, len, "ext:%s", ssid->ext_psk);
+		res = os_snprintf(buf, len, "ext:%s", ssid->ext_psk);
+		if (os_snprintf_error(len, res)) {
+			os_free(buf);
+			buf = NULL;
+		}
 		return buf;
 	}
 #endif /* CONFIG_EXT_PASSWORD */
@@ -2995,12 +3001,18 @@ int wpa_config_set_cred(struct wpa_cred *cred, const char *var,
 
 static char * alloc_int_str(int val)
 {
+	const unsigned int bufsize = 20;
 	char *buf;
+	int res;
 
-	buf = os_malloc(20);
+	buf = os_malloc(bufsize);
 	if (buf == NULL)
 		return NULL;
-	os_snprintf(buf, 20, "%d", val);
+	res = os_snprintf(buf, bufsize, "%d", val);
+	if (os_snprintf_error(bufsize, res)) {
+		os_free(buf);
+		buf = NULL;
+	}
 	return buf;
 }
 
diff --git a/wpa_supplicant/ctrl_iface.c b/wpa_supplicant/ctrl_iface.c
index ae658976e..9e1fb291c 100644
--- a/wpa_supplicant/ctrl_iface.c
+++ b/wpa_supplicant/ctrl_iface.c
@@ -2973,9 +2973,13 @@ static int wpas_ctrl_remove_cred(struct wpa_supplicant *wpa_s,
 	ssid = wpa_s->conf->ssid;
 	while (ssid) {
 		if (ssid->parent_cred == cred) {
+			int res;
+
 			wpa_printf(MSG_DEBUG, "Remove network id %d since it "
 				   "used the removed credential", ssid->id);
-			os_snprintf(str, sizeof(str), "%d", ssid->id);
+			res = os_snprintf(str, sizeof(str), "%d", ssid->id);
+			if (os_snprintf_error(sizeof(str), res))
+				str[sizeof(str) - 1] = '\0';
 			ssid = ssid->next;
 			wpa_supplicant_ctrl_iface_remove_network(wpa_s, str);
 		} else
@@ -3965,7 +3969,7 @@ static int wpa_supplicant_ctrl_iface_bss(struct wpa_supplicant *wpa_s,
 	struct dl_list *next;
 	int ret = 0;
 	int len;
-	char *ctmp;
+	char *ctmp, *end = buf + buflen;
 	unsigned long mask = WPA_BSS_MASK_ALL;
 
 	if (os_strncmp(cmd, "RANGE=", 6) == 0) {
@@ -4074,8 +4078,16 @@ static int wpa_supplicant_ctrl_iface_bss(struct wpa_supplicant *wpa_s,
 		if (bss == bsslast) {
 			if ((mask & WPA_BSS_MASK_DELIM) && len &&
 			    (bss == dl_list_last(&wpa_s->bss_id,
-						 struct wpa_bss, list_id)))
-				os_snprintf(buf - 5, 5, "####\n");
+						 struct wpa_bss, list_id))) {
+				int res;
+
+				res = os_snprintf(buf - 5, end - buf + 5,
+						  "####\n");
+				if (os_snprintf_error(end - buf + 5, res)) {
+					wpa_printf(MSG_DEBUG,
+						   "Could not add end delim");
+				}
+			}
 			break;
 		}
 		next = bss->list_id.next;
@@ -6684,8 +6696,13 @@ static void wpas_ctrl_vendor_elem_update(struct wpa_supplicant *wpa_s)
 
 	for (i = 0; i < NUM_VENDOR_ELEM_FRAMES; i++) {
 		if (wpa_s->vendor_elem[i]) {
-			os_snprintf(buf, sizeof(buf), "frame[%u]", i);
-			wpa_hexdump_buf(MSG_DEBUG, buf, wpa_s->vendor_elem[i]);
+			int res;
+
+			res = os_snprintf(buf, sizeof(buf), "frame[%u]", i);
+			if (!os_snprintf_error(sizeof(buf), res)) {
+				wpa_hexdump_buf(MSG_DEBUG, buf,
+						wpa_s->vendor_elem[i]);
+			}
 		}
 	}
 
diff --git a/wpa_supplicant/p2p_supplicant.c b/wpa_supplicant/p2p_supplicant.c
index aac3a10d4..267b59ba6 100644
--- a/wpa_supplicant/p2p_supplicant.c
+++ b/wpa_supplicant/p2p_supplicant.c
@@ -1557,8 +1557,12 @@ static void wpas_p2p_get_group_ifname(struct wpa_supplicant *wpa_s,
 	os_snprintf(ifname, len, "p2p-%s-%d", ifname_ptr, wpa_s->p2p_group_idx);
 	if (os_strlen(ifname) >= IFNAMSIZ &&
 	    os_strlen(wpa_s->ifname) < IFNAMSIZ) {
+		int res;
+
 		/* Try to avoid going over the IFNAMSIZ length limit */
-		os_snprintf(ifname, len, "p2p-%d", wpa_s->p2p_group_idx);
+		res = os_snprintf(ifname, len, "p2p-%d", wpa_s->p2p_group_idx);
+		if (os_snprintf_error(len, res) && len)
+			ifname[len - 1] = '\0';
 	}
 }
 
@@ -2948,6 +2952,7 @@ static void wpas_prov_disc_req(void *ctx, const u8 *peer, u16 config_methods,
 	u8 empty_dev_type[8];
 	unsigned int generated_pin = 0;
 	struct wpa_supplicant *group = NULL;
+	int res;
 
 	if (group_id) {
 		for (group = wpa_s->global->ifaces; group; group = group->next)
@@ -2966,15 +2971,17 @@ static void wpas_prov_disc_req(void *ctx, const u8 *peer, u16 config_methods,
 		os_memset(empty_dev_type, 0, sizeof(empty_dev_type));
 		pri_dev_type = empty_dev_type;
 	}
-	os_snprintf(params, sizeof(params), " p2p_dev_addr=" MACSTR
-		    " pri_dev_type=%s name='%s' config_methods=0x%x "
-		    "dev_capab=0x%x group_capab=0x%x%s%s",
-		    MAC2STR(dev_addr),
-		    wps_dev_type_bin2str(pri_dev_type, devtype,
-					 sizeof(devtype)),
-		    dev_name, supp_config_methods, dev_capab, group_capab,
-		    group ? " group=" : "",
-		    group ? group->ifname : "");
+	res = os_snprintf(params, sizeof(params), " p2p_dev_addr=" MACSTR
+			  " pri_dev_type=%s name='%s' config_methods=0x%x "
+			  "dev_capab=0x%x group_capab=0x%x%s%s",
+			  MAC2STR(dev_addr),
+			  wps_dev_type_bin2str(pri_dev_type, devtype,
+					       sizeof(devtype)),
+			  dev_name, supp_config_methods, dev_capab, group_capab,
+			  group ? " group=" : "",
+			  group ? group->ifname : "");
+	if (os_snprintf_error(sizeof(params), res))
+		wpa_printf(MSG_DEBUG, "P2P: PD Request event truncated");
 	params[sizeof(params) - 1] = '\0';
 
 	if (config_methods & WPS_CONFIG_DISPLAY) {
@@ -3010,10 +3017,14 @@ static void wpas_prov_disc_resp(void *ctx, const u8 *peer, u16 config_methods)
 	}
 
 	if (wpa_s->pending_pd_use == AUTO_PD_JOIN ||
-	    wpa_s->pending_pd_use == AUTO_PD_GO_NEG)
-		os_snprintf(params, sizeof(params), " peer_go=%d",
-			    wpa_s->pending_pd_use == AUTO_PD_JOIN);
-	else
+	    wpa_s->pending_pd_use == AUTO_PD_GO_NEG) {
+		int res;
+
+		res = os_snprintf(params, sizeof(params), " peer_go=%d",
+				  wpa_s->pending_pd_use == AUTO_PD_JOIN);
+		if (os_snprintf_error(sizeof(params), res))
+			params[sizeof(params) - 1] = '\0';
+	} else
 		params[0] = '\0';
 
 	if (config_methods & WPS_CONFIG_DISPLAY)
@@ -3921,8 +3932,10 @@ int wpas_p2p_add_p2pdev_interface(struct wpa_supplicant *wpa_s,
 	char force_name[100];
 	int ret;
 
-	os_snprintf(ifname, sizeof(ifname), P2P_MGMT_DEVICE_PREFIX "%s",
-		    wpa_s->ifname);
+	ret = os_snprintf(ifname, sizeof(ifname), P2P_MGMT_DEVICE_PREFIX "%s",
+			  wpa_s->ifname);
+	if (os_snprintf_error(sizeof(ifname), ret))
+		return -1;
 	force_name[0] = '\0';
 	wpa_s->pending_interface_type = WPA_IF_P2P_DEVICE;
 	ret = wpa_drv_if_add(wpa_s, WPA_IF_P2P_DEVICE, ifname, NULL, NULL,
@@ -4968,8 +4981,10 @@ int wpas_p2p_connect(struct wpa_supplicant *wpa_s, const u8 *peer_addr,
 		os_strlcpy(wpa_s->p2p_pin, pin, sizeof(wpa_s->p2p_pin));
 	else if (wps_method == WPS_PIN_DISPLAY) {
 		ret = wps_generate_pin();
-		os_snprintf(wpa_s->p2p_pin, sizeof(wpa_s->p2p_pin), "%08d",
-			    ret);
+		res = os_snprintf(wpa_s->p2p_pin, sizeof(wpa_s->p2p_pin),
+				  "%08d", ret);
+		if (os_snprintf_error(sizeof(wpa_s->p2p_pin), res))
+			wpa_s->p2p_pin[sizeof(wpa_s->p2p_pin) - 1] = '\0';
 		wpa_printf(MSG_DEBUG, "P2P: Randomly generated PIN: %s",
 			   wpa_s->p2p_pin);
 	} else
@@ -6268,11 +6283,16 @@ void wpas_p2p_completed(struct wpa_supplicant *wpa_s)
 
 	ip_addr[0] = '\0';
 	if (wpa_sm_get_p2p_ip_addr(wpa_s->wpa, ip) == 0) {
-		os_snprintf(ip_addr, sizeof(ip_addr), " ip_addr=%u.%u.%u.%u "
-			    "ip_mask=%u.%u.%u.%u go_ip_addr=%u.%u.%u.%u",
-			    ip[0], ip[1], ip[2], ip[3],
-			    ip[4], ip[5], ip[6], ip[7],
-			    ip[8], ip[9], ip[10], ip[11]);
+		int res;
+
+		res = os_snprintf(ip_addr, sizeof(ip_addr),
+				  " ip_addr=%u.%u.%u.%u "
+				  "ip_mask=%u.%u.%u.%u go_ip_addr=%u.%u.%u.%u",
+				  ip[0], ip[1], ip[2], ip[3],
+				  ip[4], ip[5], ip[6], ip[7],
+				  ip[8], ip[9], ip[10], ip[11]);
+		if (os_snprintf_error(sizeof(ip_addr), res))
+			ip_addr[0] = '\0';
 	}
 
 	wpas_p2p_group_started(wpa_s, 0, ssid, freq,