Re: [PATCH net v2] net: sched: fix possible refcount leak in tc_chain_tmplt_add()

[Larysa Zaremba <larysa.zaremba@intel.com>]

On Wed, Jun 07, 2023 at 10:23:01AM +0800, Hangyu Hua wrote:
> try_module_get will be called in tcf_proto_lookup_ops. So module_put needs
> to be called to drop the refcount if ops don't implement the required
> function.
> 
> Fixes: 9f407f1768d3 ("net: sched: introduce chain templates")

Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>

> Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
> ---
> 	
> 	v2: fix the patch description.
> 
>  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 2621550bfddc..92bfb892e638 100644
> --- a/net/sched/cls_api.c
> +++ b/net/sched/cls_api.c
> @@ -2952,6 +2952,7 @@ static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
>  		return PTR_ERR(ops);
>  	if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
>  		NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
> +		module_put(ops->owner);
>  		return -EOPNOTSUPP;
>  	}
>  
> -- 
> 2.34.1
>