2022-09-21 09:13:30

by Hangyu Hua

Subject: [PATCH] net: sched: act_ct: fix possible refcount leak in tcf_ct_init()

nf_ct_put need to be called to put the refcount got by tcf_ct_fill_params
to avoid possible refcount leak when tcf_ct_flow_table_get fails.

Fixes: c34b961a2492 ("net/sched: act_ct: Create nf flow table per zone")
Signed-off-by: Hangyu Hua <[email protected]>
---
net/sched/act_ct.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
index d55afb8d14be..3646956fc717 100644
--- a/net/sched/act_ct.c
+++ b/net/sched/act_ct.c
@@ -1412,6 +1412,8 @@ static int tcf_ct_init(struct net *net, struct nlattr *nla,
cleanup:
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
+ if (params->tmpl)
+ nf_ct_put(params->tmpl);
kfree(params);
tcf_idr_release(*a, bind);
return err;
--
2.34.1

2022-09-22 14:33:29

by Jakub Kicinski

Subject: Re: [PATCH] net: sched: act_ct: fix possible refcount leak in tcf_ct_init()

On Wed, 21 Sep 2022 17:06:00 +0800 Hangyu Hua wrote:
> Subject: [PATCH] net: sched: act_ct: fix possible refcount leak in tcf_ct_init()

[PATCH net] please

> nf_ct_put need to be called to put the refcount got by tcf_ct_fill_params
> to avoid possible refcount leak when tcf_ct_flow_table_get fails.
>
> Fixes: c34b961a2492 ("net/sched: act_ct: Create nf flow table per zone")
> Signed-off-by: Hangyu Hua <[email protected]>
> ---
> net/sched/act_ct.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/net/sched/act_ct.c b/net/sched/act_ct.c
> index d55afb8d14be..3646956fc717 100644
> --- a/net/sched/act_ct.c
> +++ b/net/sched/act_ct.c
> @@ -1412,6 +1412,8 @@ static int tcf_ct_init(struct net *net, struct nlattr *nla,
> cleanup:
> if (goto_ch)
> tcf_chain_put_by_act(goto_ch);
> + if (params->tmpl)
> + nf_ct_put(params->tmpl);

This is buggy, params could be NULL here. Please add a new label above
cleanup (cleanup_params for example) and make the
tcf_ct_flow_table_get() failure path jump there instead.