fix out-of-bounds reads in __dns_parse

[musl] / src / network / getnameinfo.c

diff --git a/src/network/getnameinfo.c b/src/network/getnameinfo.c
index 3484fc6..949e181 100644 (file)
--- a/src/network/getnameinfo.c
+++ b/src/network/getnameinfo.c
@@ -2,19 +2,16 @@
 #include <limits.h>
 #include <string.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <arpa/inet.h>
 #include <net/if.h>
 #include <ctype.h>
+#include <resolv.h>
 #include "lookup.h"
 #include "stdio_impl.h"
 
-int __dns_parse(const unsigned char *, int, int (*)(void *, int, const void *, int, const void *), void *);
-int __dn_expand(const unsigned char *, const unsigned char *, const unsigned char *, char *, int);
-int __res_mkquery(int, const char *, int, int, const unsigned char *, int, const unsigned char*, unsigned char *, int);
-int __res_send(const unsigned char *, int, unsigned char *, int);
-
 #define PTR_MAX (64 + sizeof ".in-addr.arpa")
 #define RR_PTR 12
 
@@ -135,13 +132,13 @@ int getnameinfo(const struct sockaddr *restrict sa, socklen_t sl,
        switch (af) {
        case AF_INET:
                a = (void *)&((struct sockaddr_in *)sa)->sin_addr;
-               if (sl != sizeof(struct sockaddr_in)) return EAI_FAMILY;
+               if (sl < sizeof(struct sockaddr_in)) return EAI_FAMILY;
                mkptr4(ptr, a);
                scopeid = 0;
                break;
        case AF_INET6:
                a = (void *)&((struct sockaddr_in6 *)sa)->sin6_addr;
-               if (sl != sizeof(struct sockaddr_in6)) return EAI_FAMILY;
+               if (sl < sizeof(struct sockaddr_in6)) return EAI_FAMILY;
                if (memcmp(a, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12))
                        mkptr6(ptr, a);
                else
@@ -161,6 +158,7 @@ int getnameinfo(const struct sockaddr *restrict sa, socklen_t sl,
                        unsigned char query[18+PTR_MAX], reply[512];
                        int qlen = __res_mkquery(0, ptr, 1, RR_PTR,
                                0, 0, 0, query, sizeof query);
+                       query[3] = 0; /* don't need AD flag */
                        int rlen = __res_send(query, qlen, reply, sizeof reply);
                        buf[0] = 0;
                        if (rlen > 0)