From: Phi Nguyen <phind.uet@gmail.com>
To: Eric Dumazet <edumazet@google.com>
Cc: "Song Liu" <songliubraving@fb.com>,
"Alexander Lobakin" <alobakin@pm.me>,
syzbot+989efe781c74de1ddb54@syzkaller.appspotmail.com,
"Alexei Starovoitov" <ast@kernel.org>,
"Wei Wang" <weiwan@google.com>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"John Fastabend" <john.fastabend@gmail.com>,
"Andrii Nakryiko" <andrii@kernel.org>,
"Yonghong Song" <yhs@fb.com>,
linux-kernel-mentees@lists.linuxfoundation.org,
"Jesper Dangaard Brouer" <hawk@kernel.org>,
kpsingh@kernel.org, memxor@gmail.com,
"Jakub Kicinski" <kuba@kernel.org>,
netdev <netdev@vger.kernel.org>,
"Antoine Tenart" <atenart@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
"David Miller" <davem@davemloft.net>,
"Björn Töpel" <bjorn@kernel.org>, bpf <bpf@vger.kernel.org>,
"Martin KaFai Lau" <kafai@fb.com>,
"Taehee Yoo" <ap420073@gmail.com>
Subject: Re: [PATCH] net: drop skbs in napi->rx_list when removing the napi context.
Date: Fri, 13 Aug 2021 03:17:18 +0800 [thread overview]
Message-ID: <663ac8c4-b0c3-5af6-c3c3-f371e0410a43@gmail.com> (raw)
In-Reply-To: <CANn89iLQj4Xm-6Bcygtkd5QqDzmJBDALznL8mEJrF1Fh_W32iQ@mail.gmail.com>
On 8/12/2021 3:07 PM, Eric Dumazet wrote:
> Also I object to this fix.
>
> If packets have been stored temporarily in GRO, they should be
> released at some point,
> normally at the end of a napi poll.
>
> By released, I mean that these packets should reach the upper stack,
> instead of being dropped without
> any notification.
>
> It seems a call to gro_normal_list() is missing somewhere.
>
> Can you find where ?
>
> Thanks !
> H Eric,
I think the location that should have a call to gro_normal_list() is
__netif_napi_del(). Let say, if the driver call a function that lead to
gro_normal_one(), and add a skb to the rx_list while the napi poll is
not scheduled, and the driver remove the napi context before a napi poll
could be triggered, then the added skb will be lost.
Actually, this was the first solution that I tried with syzbot (It
passed the test too).
Best regards,
Phi
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next prev parent reply other threads:[~2021-08-12 19:17 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-11 23:59 [PATCH] net: drop skbs in napi->rx_list when removing the napi context Nguyen Dinh Phi
2021-08-12 4:50 ` Hillf Danton
2021-08-12 5:19 ` [syzbot] memory leak in packet_sendmsg syzbot
2021-08-12 7:07 ` [PATCH] net: drop skbs in napi->rx_list when removing the napi context Eric Dumazet via Linux-kernel-mentees
2021-08-12 19:17 ` Phi Nguyen [this message]
2021-08-13 10:16 ` Eric Dumazet
2021-08-13 10:51 ` Nguyen Dinh Phi
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