MDEV-22950 : fix race condition in dbug

FreeState() zeros init_settings.out_file, which another thread can be using
MariaDB · Jun 19, 2020 · 727252f · 727252f
1 parent 26907e7
commit 727252f
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/dbug/dbug.c b/dbug/dbug.c
@@ -483,17 +483,17 @@ static int DbugParse(CODE_STATE *cs, const char *control)
   rel= control[0] == '+' || control[0] == '-';
   if ((!rel || (!stack->out_file && !stack->next)))
   {
+    LockIfInitSettings(cs);
     FreeState(cs, 0);
     stack->flags= 0;
     stack->delay= 0;
     stack->maxdepth= 0;
     stack->sub_level= 0;
     stack->out_file= sstderr;
     stack->functions= NULL;
-    LockIfInitSettings(cs);
     stack->keywords= NULL;
-    UnlockIfInitSettings(cs);
     stack->processes= NULL;
+    UnlockIfInitSettings(cs);
   }
   else if (!stack->out_file)
   {