diff --git a/src/multibyte/wcsrtombs.c b/src/multibyte/wcsrtombs.c
index 5cf8f3e..30be415 100644
--- a/src/multibyte/wcsrtombs.c
+++ b/src/multibyte/wcsrtombs.c
@@ -21,8 +21,13 @@ size_t wcsrtombs(char *restrict s, const wchar_t **restrict ws, size_t n, mbstat
 		}
 		return n;
 	}
-	while (n>=4 && **ws) {
-		if (**ws >= 0x80u) {
+	while (n>=4) {
+		if (**ws-1u >= 0x7fu) {
+			if (!**ws) {
+				*s = 0;
+				*ws = 0;
+				return N-n;
+			}
 			l = wcrtomb(s, **ws, 0);
 			if (!(l+1)) return -1;
 			s += l;
@@ -33,8 +38,13 @@ size_t wcsrtombs(char *restrict s, const wchar_t **restrict ws, size_t n, mbstat
 		}
 		(*ws)++;
 	}
-	while (n && **ws) {
-		if (**ws >= 0x80u) {
+	while (n) {
+		if (**ws-1u >= 0x7fu) {
+			if (!**ws) {
+				*s = 0;
+				*ws = 0;
+				return N-n;
+			}
 			l = wcrtomb(buf, **ws, 0);
 			if (!(l+1)) return -1;
 			if (l>n) return N-n;
@@ -47,7 +57,5 @@ size_t wcsrtombs(char *restrict s, const wchar_t **restrict ws, size_t n, mbstat
 		}
 		(*ws)++;
 	}
-	if (n) *s = 0;
-	*ws = 0;
-	return N-n;
+	return N;
 }
diff --git a/src/network/dns_parse.c b/src/network/dns_parse.c
index aa0d39f..0c7a601 100644
--- a/src/network/dns_parse.c
+++ b/src/network/dns_parse.c
@@ -6,6 +6,7 @@ int __dns_parse(const unsigned char *r, int rlen, int (*callback)(void *, int, c
 	const unsigned char *p;
 	int len;
 
+	if (rlen<12) return -1;
 	if ((r[3]&15)) return 0;
 	p = r+12;
 	qdcount = r[4]*256 + r[5];
@@ -13,13 +14,13 @@ int __dns_parse(const unsigned char *r, int rlen, int (*callback)(void *, int, c
 	if (qdcount+ancount > 64) return -1;
 	while (qdcount--) {
 		while (p-r < rlen && *p-1U < 127) p++;
-		if (*p>193 || (*p==193 && p[1]>254) || p>r+506)
+		if (*p>193 || (*p==193 && p[1]>254) || p>r+rlen-6)
 			return -1;
 		p += 5 + !!*p;
 	}
 	while (ancount--) {
 		while (p-r < rlen && *p-1U < 127) p++;
-		if (*p>193 || (*p==193 && p[1]>254) || p>r+506)
+		if (*p>193 || (*p==193 && p[1]>254) || p>r+rlen-6)
 			return -1;
 		p += 1 + !!*p;
 		len = p[8]*256 + p[9];
diff --git a/src/network/lookup_name.c b/src/network/lookup_name.c
index 8d41627..0292093 100644
--- a/src/network/lookup_name.c
+++ b/src/network/lookup_name.c
@@ -151,7 +151,10 @@ static int name_from_dns(struct address buf[static MAXADDRS], char canon[static
 	for (i=0; i<nq; i++)
 		__dns_parse(abuf[i], alens[i], dns_parse_callback, &ctx);
 
-	return ctx.cnt;
+	if (ctx.cnt) return ctx.cnt;
+	if (alens[0] < 4 || (abuf[0][3] & 15) == 2) return EAI_AGAIN;
+	if ((abuf[0][3] & 15) == 3) return EAI_NONAME;
+	return EAI_FAIL;
 }
 
 int __lookup_name(struct address buf[static MAXADDRS], char canon[static 256], const char *name, int family, int flags)