local_host_ip_addrs_to_string: fix buffer overflow

HISTORY

@@ -1,4 +1,7 @@
 
+Version 1.88  2026-09-03
+ * local_host_ip_addrs_to_string: fix buffer overflow
+
 Version 1.87  2026-07-10
  * ini_file_readers can refer env variable such as %{env::FASTDFS_IPADDR}
 

src/local_ip_func.c

@@ -70,11 +70,20 @@ const char *local_host_ip_addrs_to_string(char *buff, const int size)
 
 	len = snprintf(buff, size, "local_host_ip_count: %d,",
             g_local_host_ip_count);
+    if (len >= size)
+    {
+        return buff;
+    }
+
 	pEnd = g_local_host_ip_addrs +
 		IP_ADDRESS_SIZE * g_local_host_ip_count;
 	for (p=g_local_host_ip_addrs; p<pEnd; p+=IP_ADDRESS_SIZE)
     {
         len += snprintf(buff + len, size - len, "  %s", p);
+        if (len >= size)
+        {
+            break;
+        }
     }
 
     return buff;