imv-scanner: Properly check snprintf() return value

diff --git a/src/libimcv/plugins/imv_scanner/imv_scanner_agent.c b/src/libimcv/plugins/imv_scanner/imv_scanner_agent.c
index 1d69d4de09261863f1345a5f53faa7e5bb16645a..d1e09313762e2d97198ace554c4b3223a0396360 100644 (file)
--- a/src/libimcv/plugins/imv_scanner/imv_scanner_agent.c
+++ b/src/libimcv/plugins/imv_scanner/imv_scanner_agent.c
@@ -332,7 +332,8 @@ METHOD(imv_agent_if_t, batch_ending, TNC_Result,
                u_int16_t port;
                bool closed_port_policy, blocked, first;
                char result_str[BUF_LEN], *pos, *protocol_str;
-               size_t len, written;
+               size_t len;
+               int written;
                linked_list_t *port_list;
                enumerator_t *e1, *e2;
 
@@ -410,12 +411,15 @@ METHOD(imv_agent_if_t, batch_ending, TNC_Result,
                                        {
                                                written = snprintf(pos, len, "violating %s ports:",
                                                                                                          protocol_str);
-                                               pos += written;
-                                               len -= written;
+                                               if (written > 0 && written < len)
+                                               {
+                                                       pos += written;
+                                                       len -= written;
+                                               }
                                                first = FALSE;
                                        }
                                        written = snprintf(pos, len, " %u", port);
-                                       if (written > len || written < 0)
+                                       if (written < 0 || written >= len)
                                        {
                                                pos += len - 1;
                                                *pos = '\0';
@@ -503,7 +507,7 @@ imv_agent_if_t *imv_scanner_agent_create(const char *name, TNC_IMVID id,
        {
                return NULL;
        }
-       
+
        INIT(this,
                .public = {
                        .bind_functions = _bind_functions,