Only send the signal if the pid is a positive value.

CHANGELOG.md

@@ -13,6 +13,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fork vhosts before creating the socket.[#576](https://github.com/greenbone/openvas/pull/576)
 - Check if another forked child has already added the same vhost. [#581](https://github.com/greenbone/openvas/pull/581)
 - Send duplicated hosts as dead hosts to ospd, to adjust scan progress calculation. [#586](https://github.com/greenbone/openvas/pull/586)
+- Only send the signal if the pid is a positive value. [#593](https://github.com/greenbone/openvas/pull/593)
 
 [20.08]: https://github.com/greenbone/openvas/compare/v20.8.0...openvas-20.08
 

src/openvas.c

@@ -408,6 +408,13 @@ stop_single_task_scan (void)
     exit (1);
 
   pid = kb_item_get_int (kb, "internal/ovas_pid");
+
+  /* Only send the signal if the pid is a positive value.
+     Since kb_item_get_int() will return -1 if the key does
+     not exist. killing with -1 pid will send the signal system wide.
+   */
+  if (pid <= 0)
+    return;
   kill (pid, SIGUSR1);
 
   exit (0);