ntpd plugin: Fix dereference of type-punned pointer.

diff --git a/src/ntpd.c b/src/ntpd.c
index 44964bb..4bc3139 100644 (file)
--- a/src/ntpd.c
+++ b/src/ntpd.c
@@ -896,25 +896,33 @@ static int ntpd_read (void)
 
                        if (ptr->v6_flag)
                        {
-                               struct sockaddr_in6 *sa_ptr;
-                               sa_ptr = (struct sockaddr_in6 *) &sa;
+                               struct sockaddr_in6 sa6;
 
-                               sa_ptr->sin6_family = AF_INET6;
-                               sa_ptr->sin6_port = htons (123);
-                               memcpy (&sa_ptr->sin6_addr, &ptr->srcadr6,
+                               assert (sizeof (sa) >= sizeof (sa6));
+
+                               memset (&sa6, 0, sizeof (sa6));
+                               sa6.sin6_family = AF_INET6;
+                               sa6.sin6_port = htons (123);
+                               memcpy (&sa6.sin6_addr, &ptr->srcadr6,
                                                sizeof (struct in6_addr));
-                               sa_len = sizeof (struct sockaddr_in6);
+                               sa_len = sizeof (sa6);
+
+                               memcpy (&sa, &sa6, sizeof (sa6));
                        }
                        else
                        {
-                               struct sockaddr_in *sa_ptr;
-                               sa_ptr = (struct sockaddr_in *) &sa;
+                               struct sockaddr_in sa4;
 
-                               sa_ptr->sin_family = AF_INET;
-                               sa_ptr->sin_port = htons (123);
-                               memcpy (&sa_ptr->sin_addr, &ptr->srcadr,
+                               assert (sizeof (sa) >= sizeof (sa4));
+
+                               memset (&sa4, 0, sizeof (sa4));
+                               sa4.sin_family = AF_INET;
+                               sa4.sin_port = htons (123);
+                               memcpy (&sa4.sin_addr, &ptr->srcadr,
                                                sizeof (struct in_addr));
-                               sa_len = sizeof (struct sockaddr_in);
+                               sa_len = sizeof (sa4);
+
+                               memcpy (&sa, &sa4, sizeof (sa4));
                        }
 
                        if (do_reverse_lookups == 0)