Re: [PATCH] sch_gred: kzalloc needs null check

From: Eric Dumazet
Date: Thu Jul 18 2019 - 21:42:58 EST




On 7/19/19 3:30 AM, Navid Emamdoost wrote:
> call to kzalloc may fail and return null. So the result should be checked
> against null. Added the check to cover kzalloc failure case.
>
> Signed-off-by: Navid Emamdoost <navid.emamdoost@xxxxxxxxx>
> ---
> net/sched/sch_gred.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
> index 8599c6f31b05..5cd0859f0274 100644
> --- a/net/sched/sch_gred.c
> +++ b/net/sched/sch_gred.c
> @@ -697,6 +697,9 @@ static int gred_change(struct Qdisc *sch, struct nlattr *opt,
> }
>
> prealloc = kzalloc(sizeof(*prealloc), GFP_KERNEL);
> + if (!prealloc)
> + return -ENOMEM;
> +
> sch_tree_lock(sch);
>
> err = gred_change_vq(sch, ctl->DP, ctl, prio, stab, max_P, &prealloc,
>

This seems not needed.

The case is handled later in gred_change_vq()