diff --git a/src/args.c b/src/args.c
index b8b66d4..20077c4 100644
--- a/src/args.c
+++ b/src/args.c
@@ -62,14 +62,18 @@ static int read_file(const char* filename) {
 	}
 
 	ret = fseek(fd, 0, SEEK_END);
-	if (ret < 0) {
+	if (ret != 0) {
 		ret = -errno;
 		goto close_file;
 	}
 
-	size_t fsize = ftell(fd);
-	fseek(fd, 0, SEEK_SET);
-	if (ret < 0) {
+	long fsize = ftell(fd);
+	if (fsize == -1L) {
+		ret = -errno;
+		goto close_file;
+	}
+	ret = fseek(fd, 0, SEEK_SET);
+	if (ret != 0) {
 		ret = -errno;
 		goto close_file;
 	}
@@ -120,10 +124,10 @@ static int parse_sni_domains(struct domains_list **dlist, const char *domains_st
 			unsigned int domain_len = (i - j);
 			const char *domain_startp = domains_str + j;
 			struct domains_list *edomain = malloc(sizeof(struct domains_list));
-			*edomain = (struct domains_list){0};
 			if (edomain == NULL) {
 				return -ENOMEM;
 			}
+			*edomain = (struct domains_list){0};
 
 			edomain->domain_len = domain_len;
 			edomain->domain_name = malloc(domain_len + 1);
@@ -285,6 +289,9 @@ static int parse_fake_custom_payload(
 		return -EINVAL;
 	}
 	unsigned char *custom_buf = malloc(custom_len);
+	if (custom_buf == NULL) {
+		return -ENOMEM;
+	}
 
 	for (int i = 0; i < custom_len; i++) {
 		ret = sscanf(custom_hex_fake + (i << 1), "%2hhx", custom_buf + i);
@@ -1242,11 +1249,11 @@ int init_section_config(struct section_config_t **section, struct section_config
 #else
 	def_section = malloc(sizeof(struct section_config_t));
 #endif
-	*def_section = (struct section_config_t)default_section_config;
-	def_section->prev = prev;
-
-	if (def_section == NULL) 
+	if (def_section == NULL)
 		return -ENOMEM;
+	*def_section = (struct section_config_t)default_section_config;
+
+	def_section->prev = prev;
 
 	ret = parse_sni_domains(&def_section->sni_domains, default_snistr, sizeof(default_snistr));
 	if (ret < 0) {
diff --git a/src/mangle.c b/src/mangle.c
index cce9ccd..c299ee5 100644
--- a/src/mangle.c
+++ b/src/mangle.c
@@ -502,18 +502,11 @@ drop:
 
 int send_ip4_frags(const struct section_config_t *section, const uint8_t *packet, size_t pktlen, const size_t *poses, size_t poses_sz, size_t dvs) {
 	if (poses_sz == 0) {
+		lgtrace_addp("raw send packet of %zu bytes with %zu dvs", pktlen, dvs);
 		if (section->seg2_delay && ((dvs > 0) ^ section->frag_sni_reverse)) {
-			if (!instance_config.send_delayed_packet) {
-				return -EINVAL;
-			}
-
-			lgtrace_addp("Sent %zu delayed for %d", pktlen, section->seg2_delay);
-			instance_config.send_delayed_packet(
+			return instance_config.send_delayed_packet(
 				packet, pktlen, section->seg2_delay);
-
-			return 0;
 		} else {
-			lgtrace_addp("Sent %zu bytes", pktlen);
 			return instance_config.send_raw_packet(
 				packet, pktlen);
 		}
@@ -588,18 +581,11 @@ out:
 
 int send_tcp_frags(const struct section_config_t *section, const uint8_t *packet, size_t pktlen, const size_t *poses, size_t poses_sz, size_t dvs) {
 	if (poses_sz == 0) {
+		lgtrace_addp("raw send packet of %zu bytes with %zu dvs", pktlen, dvs);
 		if (section->seg2_delay && ((dvs > 0) ^ section->frag_sni_reverse)) {
-			if (!instance_config.send_delayed_packet) {
-				return -EINVAL;
-			}
-
-			instance_config.send_delayed_packet(
+			return instance_config.send_delayed_packet(
 				packet, pktlen, section->seg2_delay);
-
-			return 0;
 		} else {
-			lgtrace_addp("raw send packet of %zu bytes with %zu dvs", pktlen, dvs);
-
 			return instance_config.send_raw_packet(
 				packet, pktlen);
 		}
diff --git a/src/quic.c b/src/quic.c
index d4ac72f..3112bf5 100644
--- a/src/quic.c
+++ b/src/quic.c
@@ -71,7 +71,7 @@ int quic_check_is_initial(const struct quic_lhdr *qch) {
 	uint32_t qversion;
 	int ret;
 	ret = quic_get_version(&qversion, qch);
-	if (qversion < 0) return 0;
+	if (ret < 0) return 0;
 
 	uint8_t qtype = qch->type;
 
diff --git a/src/quic_crypto.c b/src/quic_crypto.c
index 5e498b3..95057d1 100644
--- a/src/quic_crypto.c
+++ b/src/quic_crypto.c
@@ -82,6 +82,10 @@ int quic_parse_initial_message(
 	ret = quic_parse_data(quic_payload, quic_plen,
 			&qch, &qch_len, &qci, &inpayload, &inplen
 	);
+	if (ret < 0) {
+		lgerror(ret, "quic_parse_data");
+		goto error_nfr;
+	}
 
 	ret = quic_get_version(&qversion, qch);
 	if (ret < 0) {
@@ -117,10 +121,6 @@ int quic_parse_initial_message(
 	}
 
 	quic_header_len = inpayload - quic_payload;
-	if (ret < 0) {
-		lgerror(ret, "quic_parse_data");
-		goto error_nfr;
-	}
 
 	ret = quic_parse_initial_header(inpayload, inplen, &qich);
 	if (ret < 0) {
diff --git a/src/youtubeUnblock.c b/src/youtubeUnblock.c
index 8c5bffe..8eed35b 100644
--- a/src/youtubeUnblock.c
+++ b/src/youtubeUnblock.c
@@ -614,14 +614,33 @@ void *delay_packet_send_fn(void *data) {
 }
 
 int delay_packet_send(const unsigned char *data, size_t data_len, unsigned int delay_ms) {
+	int ret;
+
 	struct dps_t *dpdt = malloc(sizeof(struct dps_t));
+	if (dpdt == NULL) {
+		return -ENOMEM;
+	}
+	*dpdt = (struct dps_t){0};
+
 	dpdt->pkt = malloc(data_len);
+	if (dpdt->pkt == NULL) {
+		free(dpdt);
+		return -ENOMEM;
+	}
 	memcpy(dpdt->pkt, data, data_len);
+
 	dpdt->pktlen = data_len;
 	dpdt->timer = delay_ms;
-	pthread_t thr;
-	pthread_create(&thr, NULL, delay_packet_send_fn, dpdt);
-	pthread_detach(thr);
+	pthread_t thr = {0};
+	ret = pthread_create(&thr, NULL, delay_packet_send_fn, dpdt);
+	if (ret != 0) {
+		free(dpdt->pkt);
+		free(dpdt);
+		return -ret;
+	}
+
+	ret = pthread_detach(thr);
+
 	lgtrace_addp("Scheduled packet send after %d ms", delay_ms);
 
 	return 0;