From mboxrd@z Thu Jan  1 00:00:00 1970
From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@toke.dk>
Subject: Re: [PATCH 1/4] sched: Avoid dereferencing skb pointer after child enqueue
Date: Wed, 09 Jan 2019 09:14:10 +0100
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References: <20190107194733.31138-1-toke@toke.dk> <20190107194733.31138-2-toke@toke.dk> <CAM_iQpVcw3+Crg_1vR4sPfG2v+arQVMY2yzBjp7yw296xCaN6Q@mail.gmail.com>
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Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
        Cake List <cake@lists.bufferbloat.net>,
        Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= <toke@redhat.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
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Cong Wang <xiyou.wangcong@gmail.com> writes:

> On Mon, Jan 7, 2019 at 11:50 AM Toke H=C3=B8iland-J=C3=B8rgensen <toke@to=
ke.dk> wrote:
>> @@ -1254,7 +1256,7 @@ static int qfq_enqueue(struct sk_buff *skb, struct=
 Qdisc *sch,
>>         if (cl->qdisc->q.qlen !=3D 1) {
>>                 if (unlikely(skb =3D=3D cl->qdisc->ops->peek(cl->qdisc))=
 &&
>
>
> Isn't this comparison problematic too? While you are on it...

Well, I was only looking at safety issues, and since it's not
dereferencing the pointer, that's not really an issue here. The check is
just going to always fail if GSO splitting is enabled. Which I'm not
actually sure is an error in this case?

-Toke