From: Paolo Abeni <pabeni@redhat.com>
To: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Network Development <netdev@vger.kernel.org>,
Willem de Bruijn <willemb@google.com>,
Miaohe Lin <linmiaohe@huawei.com>,
Jakub Kicinski <kuba@kernel.org>
Subject: Re: [PATCH net 1/4] net: fix double-free on fraglist GSO skbs
Date: Mon, 10 May 2021 17:37:58 +0200 [thread overview]
Message-ID: <3e41198f79b4d63812e3862ca688507bf3f7d65d.camel@redhat.com> (raw)
In-Reply-To: <6f4db46541880179766a30cf6d5e47f44190b98d.camel@redhat.com>
On Fri, 2021-05-07 at 10:46 +0200, Paolo Abeni wrote:
> On Thu, 2021-05-06 at 14:17 -0700, Jakub Kicinski wrote:
> > On Thu, 06 May 2021 17:55:36 +0200 Paolo Abeni wrote:
> > > On Thu, 2021-05-06 at 10:32 -0400, Willem de Bruijn wrote:
> > > > On Thu, May 6, 2021 at 7:07 AM Paolo Abeni <pabeni@redhat.com> wrote:
> > > > > If we want to be safe about future possible sock_wfree users, I think
> > > > > the approach here should be different: in skb_segment(), tail-
> > > > > > destructor is expected to be NULL, while skb_segment_list(), all the
> > > > > list skbs can be owned by the same socket. Possibly we could open-
> > > > > code skb_release_head_state(), omitting the skb orphaning part
> > > > > for sock_wfree() destructor.
> > > > >
> > > > > Note that the this is not currently needed - sock_wfree destructor
> > > > > can't reach there.
> > > > >
> > > > > Given all the above, I'm unsure if you are fine with (or at least do
> > > > > not oppose to) the code proposed in this patch?
> > > >
> > > > Yes. Thanks for clarifying, Paolo.
> > >
> > > Thank you for reviewing!
> > >
> > > @David, @Jakub: I see this series is already archived as "change
> > > requested", should I repost?
> >
> > Yes, please. Patch 2 adds two new sparse warnings.
> >
> > I think you need csum_unfold() to go from __sum16 to __wsum.
>
> Yes, indeed. I'll send a v2 with such change, thanks!
It's taking [much] more than expected, as it turned out that thare are
still a number of case where the tx csum is uncorrect.
If the traffic comes from a veth we don't have a valid th->csum value
at GRO time, setting ip_summed to CHECKSUM_UNNECESSARY - as the current
code does - looks wrong.
@Steffen: I see in the original discussion about GRO_FRAGLIST
introduction that you wanted the GRO packets to be CHECKSUM_UNNECESSARY
to avoid csum modification in fwd path. I guess that choice was mostily
due performance reasons, to avoid touching the aggregated pkts header
at gso_segment_list time, but it looks like it's quite bug prone. If
so, I'm unsure the performance gain is worty. I propose to switch to
CHECKSUM_PARTIAL. Would you be ok with that?
Thanks,
Paolo
next prev parent reply other threads:[~2021-05-10 15:39 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-05 15:35 [PATCH net 0/4] udp: more FRAGLIST fixes Paolo Abeni
2021-05-05 15:35 ` [PATCH net 1/4] net: fix double-free on fraglist GSO skbs Paolo Abeni
2021-05-05 16:13 ` Willem de Bruijn
2021-05-05 17:28 ` Paolo Abeni
2021-05-05 17:30 ` Willem de Bruijn
2021-05-06 11:06 ` Paolo Abeni
2021-05-06 14:32 ` Willem de Bruijn
2021-05-06 15:55 ` Paolo Abeni
2021-05-06 21:17 ` Jakub Kicinski
2021-05-07 8:46 ` Paolo Abeni
2021-05-10 15:37 ` Paolo Abeni [this message]
2021-05-11 9:39 ` Steffen Klassert
2021-05-05 15:35 ` [PATCH net 2/4] udp: fix out-of-bound at segmentation time Paolo Abeni
2021-05-05 15:35 ` [PATCH net 3/4] udp: fix outer header csum for SKB_GSO_FRAGLIST over UDP tunnel Paolo Abeni
2021-05-05 15:35 ` [PATCH net 4/4] selftests: more UDP GRO tests Paolo Abeni
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