From: "Toke Høiland-Jørgensen" <toke@toke.dk>
To: Eric Dumazet <edumazet@google.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>,
Cong Wang <xiyou.wangcong@gmail.com>,
Jiri Pirko <jiri@resnulli.us>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
cake@lists.bufferbloat.net, netdev <netdev@vger.kernel.org>
Subject: Re: [PATCH net] sch_cake: Return __NET_XMIT_STOLEN when consuming enqueued skb
Date: Wed, 31 Aug 2022 23:31:38 +0200 [thread overview]
Message-ID: <875yi83xs5.fsf@toke.dk> (raw)
In-Reply-To: <CANn89iKiJ91D7fELw9iKB4yCLaDj-WEv27wRS4PtLqM7oK8m=w@mail.gmail.com>
Eric Dumazet <edumazet@google.com> writes:
> On Wed, Aug 31, 2022 at 2:25 AM Toke Høiland-Jørgensen <toke@toke.dk> wrote:
>>
>> When the GSO splitting feature of sch_cake is enabled, GSO superpackets
>> will be broken up and the resulting segments enqueued in place of the
>> original skb. In this case, CAKE calls consume_skb() on the original skb,
>> but still returns NET_XMIT_SUCCESS. This can confuse parent qdiscs into
>> assuming the original skb still exists, when it really has been freed. Fix
>> this by adding the __NET_XMIT_STOLEN flag to the return value in this case.
>>
>
> I think you forgot to give credits to the team who discovered this issue.
>
> Something like this
>
> Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-18231
Ah, right; apologies, will respin!
It also looks like fixing it this way will actually break other things
(most notably sch_cake as a child of sch_htb), so will send a different
patch as v2...
-Toke
next prev parent reply other threads:[~2022-08-31 21:31 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-31 9:21 [PATCH net] sch_cake: Return __NET_XMIT_STOLEN when consuming enqueued skb Toke Høiland-Jørgensen
2022-08-31 17:08 ` Eric Dumazet
2022-08-31 21:31 ` Toke Høiland-Jørgensen [this message]
2022-08-31 21:52 ` [PATCH net v2] sch_sfb: Don't assume the skb is still around after enqueueing to child Toke Høiland-Jørgensen
2022-09-02 11:30 ` patchwork-bot+netdevbpf
2022-09-05 17:55 ` Cong Wang
2022-09-05 19:05 ` Toke Høiland-Jørgensen
2022-08-31 22:00 ` [PATCH net] sch_cake: Return __NET_XMIT_STOLEN when consuming enqueued skb patchwork-bot+netdevbpf
2022-08-31 22:13 ` Toke Høiland-Jørgensen
2022-09-01 3:07 ` Jakub Kicinski
2022-09-01 9:20 ` Toke Høiland-Jørgensen
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