prevent CNAME/PTR parsing from reading data past the response end

[musl] / src / network / getnameinfo.c

diff --git a/src/network/getnameinfo.c b/src/network/getnameinfo.c
index 949e181..080d3c0 100644 (file)
--- a/src/network/getnameinfo.c
+++ b/src/network/getnameinfo.c
@@ -108,10 +108,10 @@ static void reverse_services(char *buf, int port, int dgram)
        __fclose_ca(f);
 }
 
-static int dns_parse_callback(void *c, int rr, const void *data, int len, const void *packet)
+static int dns_parse_callback(void *c, int rr, const void *data, int len, const void *packet, int plen)
 {
        if (rr != RR_PTR) return 0;
-       if (__dn_expand(packet, (const unsigned char *)packet + 512,
+       if (__dn_expand(packet, (const unsigned char *)packet + plen,
            data, c, 256) <= 0)
                *(char *)c = 0;
        return 0;