vlib: Counter free needs to NULL the allocated counter vector

otherwise the next time the counter is validated this is dangling.

Type: fix
Fixes: 58fd481d73

Signed-off-by: Neale Ranns <neale@graphiant.com>
Change-Id: Ifa8d5ff27175cf6dfb30cbf023fa3251fe5c780e

2 files changed, 14 insertions, 2 deletions

diff --git a/src/plugins/unittest/counter_test.c b/src/plugins/unittest/counter_test.c
index 65c03fe89f1..71f8f93f94d 100644
--- a/src/plugins/unittest/counter_test.c
+++ b/src/plugins/unittest/counter_test.c
@@ -89,6 +89,9 @@ test_simple_counter_expand (vlib_main_t *vm)
       epoch = new_epoch;
     }
 
+  vlib_free_simple_counter (&counter);
+  vlib_validate_simple_counter (&counter, 0);
+
   return 0;
 }
 
@@ -136,6 +139,9 @@ test_combined_counter_expand (vlib_main_t *vm)
       epoch = new_epoch;
     }
 
+  vlib_free_combined_counter (&counter);
+  vlib_validate_combined_counter (&counter, 0);
+
   return 0;
 }
 
diff --git a/src/vlib/counter.c b/src/vlib/counter.c
index 4f375dee938..9f14d02909f 100644
--- a/src/vlib/counter.c
+++ b/src/vlib/counter.c
@@ -108,7 +108,10 @@ vlib_free_simple_counter (vlib_simple_counter_main_t * cm)
       vec_free (cm->counters);
     }
   else
-    vlib_stats_remove_entry (cm->stats_entry_index);
+    {
+      vlib_stats_remove_entry (cm->stats_entry_index);
+      cm->counters = NULL;
+    }
 }
 
 void
@@ -176,7 +179,10 @@ vlib_free_combined_counter (vlib_combined_counter_main_t * cm)
       vec_free (cm->counters);
     }
   else
-    vlib_stats_remove_entry (cm->stats_entry_index);
+    {
+      vlib_stats_remove_entry (cm->stats_entry_index);
+      cm->counters = NULL;
+    }
 }
 
 u32