* [PATCH] net: sched: gred: potential dereference of null pointer
@ 2021-12-09 2:13 Jiasheng Jiang
2021-12-09 2:36 ` Jakub Kicinski
0 siblings, 1 reply; 2+ messages in thread
From: Jiasheng Jiang @ 2021-12-09 2:13 UTC (permalink / raw)
To: jhs, xiyou.wangcong, jiri, davem, kuba
Cc: netdev, linux-kernel, Jiasheng Jiang
The return value of kzalloc() needs to be checked.
To avoid use of null pointer in gred_change_vq() in case
of the failure of alloc.
Fixes: 869aa41044b0 ("sch_gred: prefer GFP_KERNEL allocations")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
net/sched/sch_gred.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index f4132dc25ac0..c0d355281baf 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -697,6 +697,8 @@ 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,
--
2.25.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] net: sched: gred: potential dereference of null pointer
2021-12-09 2:13 [PATCH] net: sched: gred: potential dereference of null pointer Jiasheng Jiang
@ 2021-12-09 2:36 ` Jakub Kicinski
0 siblings, 0 replies; 2+ messages in thread
From: Jakub Kicinski @ 2021-12-09 2:36 UTC (permalink / raw)
To: Jiasheng Jiang; +Cc: jhs, xiyou.wangcong, jiri, davem, netdev, linux-kernel
On Thu, 9 Dec 2021 10:13:46 +0800 Jiasheng Jiang wrote:
> The return value of kzalloc() needs to be checked.
> To avoid use of null pointer in gred_change_vq() in case
> of the failure of alloc.
>
> Fixes: 869aa41044b0 ("sch_gred: prefer GFP_KERNEL allocations")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
I don't see how. Please explain in more detail. gred_change_vq() gets
a pointer to a pointer and checks if its values is NULL.
> diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
> index f4132dc25ac0..c0d355281baf 100644
> --- a/net/sched/sch_gred.c
> +++ b/net/sched/sch_gred.c
> @@ -697,6 +697,8 @@ 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,
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2021-12-09 2:36 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-12-09 2:13 [PATCH] net: sched: gred: potential dereference of null pointer Jiasheng Jiang
2021-12-09 2:36 ` Jakub Kicinski
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.