For rollback, NULL additional pointers which could point to workspace

bin/varnishd/cache/cache_fetch.c

@@ -110,6 +110,8 @@ void Bereq_Rollback(struct busyobj *bo)
 	VCL_TaskLeave(bo->privs);
 	VCL_TaskEnter(bo->privs);
 	HTTP_Clone(bo->bereq, bo->bereq0);
+	bo->filter_list = NULL;
+	bo->err_reason = NULL;
 	WS_Rollback(bo->bereq->ws, bo->ws_bo);
 	WS_Rollback(bo->ws, bo->ws_bo);
 }

bin/varnishd/cache/cache_req.c

@@ -198,6 +198,7 @@ Req_Rollback(struct req *req)
 	if (IS_TOPREQ(req))
 		VCL_TaskEnter(req->top->privs);
 	HTTP_Clone(req->http, req->http0);
+	req->filter_list = NULL;
 	if (WS_Overflowed(req->ws))
 		req->wrk->stats->ws_client_overflow++;
 	WS_Rollback(req->ws, req->ws_req);