2022-09-15 09:25:07

by Hangyu Hua

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

tfilter_put need to be called to put the refount got by tp->ops->get to
avoid possible refcount leak when chain->tmplt_ops == NULL or
chain->tmplt_ops != tp->ops.

Fixes: 7d5509fa0d3d ("net: sched: extend proto ops with 'put' callback")
Signed-off-by: Hangyu Hua <[email protected]>
---
net/sched/cls_api.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 790d6809be81..51d175f3fbcb 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -2137,6 +2137,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
}

if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
+ tfilter_put(tp, fh);
NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
err = -EINVAL;
goto errout;
--
2.34.1

2022-09-15 14:27:48

by Vlad Buslov

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

On Thu 15 Sep 2022 at 16:58, Hangyu Hua <[email protected]> wrote:
> tfilter_put need to be called to put the refount got by tp->ops->get to
> avoid possible refcount leak when chain->tmplt_ops == NULL or
> chain->tmplt_ops != tp->ops.
>
> Fixes: 7d5509fa0d3d ("net: sched: extend proto ops with 'put' callback")
> Signed-off-by: Hangyu Hua <[email protected]>
> ---

Thanks for fixing this!

Reviewed-by: Vlad Buslov <[email protected]>

> net/sched/cls_api.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
> index 790d6809be81..51d175f3fbcb 100644
> --- a/net/sched/cls_api.c
> +++ b/net/sched/cls_api.c
> @@ -2137,6 +2137,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
> }
>
> if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
> + tfilter_put(tp, fh);
> NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
> err = -EINVAL;
> goto errout;

2022-09-20 15:55:10

by Jakub Kicinski

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

On Thu, 15 Sep 2022 16:58:04 +0800 Hangyu Hua wrote:
> tfilter_put need to be called to put the refount got by tp->ops->get to

s/refount/refcount/

> avoid possible refcount leak when chain->tmplt_ops == NULL or
> chain->tmplt_ops != tp->ops.

This should say:

when cain->tmplt_ops != NULL and ...

otherwise the commit message does not match the code.

> Fixes: 7d5509fa0d3d ("net: sched: extend proto ops with 'put' callback")
> Signed-off-by: Hangyu Hua <[email protected]>
> ---
> net/sched/cls_api.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
> index 790d6809be81..51d175f3fbcb 100644
> --- a/net/sched/cls_api.c
> +++ b/net/sched/cls_api.c
> @@ -2137,6 +2137,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
> }
>
> if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
> + tfilter_put(tp, fh);
> NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
> err = -EINVAL;
> goto errout;

2022-09-21 10:03:52

by Hangyu Hua

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

On 20/9/2022 23:50, Jakub Kicinski wrote:
> On Thu, 15 Sep 2022 16:58:04 +0800 Hangyu Hua wrote:
>> tfilter_put need to be called to put the refount got by tp->ops->get to
>
> s/refount/refcount/
>
>> avoid possible refcount leak when chain->tmplt_ops == NULL or
>> chain->tmplt_ops != tp->ops.
>
> This should say:
>
> when cain->tmplt_ops != NULL and ...
>
> otherwise the commit message does not match the code.
>

My bad. I will submit a v2.

Thanks,
Hangyu

>> Fixes: 7d5509fa0d3d ("net: sched: extend proto ops with 'put' callback")
>> Signed-off-by: Hangyu Hua <[email protected]>
>> ---
>> net/sched/cls_api.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
>> index 790d6809be81..51d175f3fbcb 100644
>> --- a/net/sched/cls_api.c
>> +++ b/net/sched/cls_api.c
>> @@ -2137,6 +2137,7 @@ static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
>> }
>>
>> if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
>> + tfilter_put(tp, fh);
>> NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
>> err = -EINVAL;
>> goto errout;
>