[ovs-dev] [PATCH v2] netflow: Fix memory leak in netflow_unref.

[Greg Rose]

On Mon, 2017-05-22 at 12:55 +0800, Yunjian Wang wrote:
> The memory leak was triggered each time on calling netflow_unref() with
> containing netflow_flows. And flows need to be removed and destroyed.
> 
> Signed-off-by: Yunjian Wang <wangyunjian at huawei.com>
> ---
>  ofproto/netflow.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/ofproto/netflow.c b/ofproto/netflow.c
> index 55f7814..29c5f3e 100644
> --- a/ofproto/netflow.c
> +++ b/ofproto/netflow.c
> @@ -409,10 +409,17 @@ netflow_ref(const struct netflow *nf_)
>  void
>  netflow_unref(struct netflow *nf)
>  {
> +    struct netflow_flow *nf_flow, *next;
> +
>      if (nf && ovs_refcount_unref_relaxed(&nf->ref_cnt) == 1) {
>          atomic_count_dec(&netflow_count);
>          collectors_destroy(nf->collectors);
>          ofpbuf_uninit(&nf->packet);
> +        HMAP_FOR_EACH_SAFE (nf_flow, next, hmap_node, &nf->flows) {
> +            hmap_remove(&nf->flows, &nf_flow->hmap_node);
> +            free(nf_flow);
> +        }
> +        hmap_destroy(&nf->flows);
>          free(nf);
>      }
>  }

This looks right to me.  The only other place I see the flows freed is
when they're detected as idle.  If the flow is never detected as idle
then I don't see anywhere else that they are freed up after the xzalloc
in netflow_flow_update().

Reviewed-by: Greg Rose <gvrose8192 at gmail.com>