Adds a sanity check before use ctl:ruleRemoveTargetByTag

This commit closes the issue #1353

Author: Felipe Zimmerle

CHANGES

@@ -1,6 +1,8 @@
 DD MMM YYYY - 2.9.2 - To be released
 ------------------------------------
 
+ * Adds a sanity check before use ctl:ruleRemoveTargetByTag.
+   [Issue #1353 - @LukeP21 and @zimmerle]
  * Uses an optional global lock while manipulating collections.
    [Issues #1224 - @mturk and @zimmerle]
  * Fix collection naming problem while merging collections.

apache2/re_actions.c

@@ -1253,6 +1253,10 @@ static apr_status_t msre_action_ctl_execute(modsec_rec *msr, apr_pool_t *mptmp,
         if (msr->txcfg->debuglog_level >= 4) {
             msr_log(msr, 4, "Ctl: ruleRemoveTargetByTag tag=%s targets=%s", p1, p2);
         }
+	if (p2 == NULL) {
+            msr_log(msr, 1, "ModSecurity: Missing target for tag \"%s\"", p1);
+	    return -1;
+	}
 
     re = apr_pcalloc(msr->mp, sizeof(rule_exception));
     re->type = RULE_EXCEPTION_REMOVE_TAG;