dnsproxy: Use memmove() when discarding domain name

The memory areas can overlap so memmove() must be used.

diff --git a/src/dnsproxy.c b/src/dnsproxy.c
index f56c30c..49651a2 100644 (file)
--- a/src/dnsproxy.c
+++ b/src/dnsproxy.c
@@ -1565,7 +1565,11 @@ static int forward_dns_reply(unsigned char *reply, int reply_len, int protocol,
                         * name. In this case we end up in this branch.
                         */
                        if (domain_len > 0) {
-                               memcpy(ptr + host_len + 1,
+                               /*
+                                * Note that we must use memmove() here,
+                                * because the memory areas can overlap.
+                                */
+                               memmove(ptr + host_len + 1,
                                        ptr + host_len + domain_len + 1,
                                        reply_len - (ptr - reply + domain_len));