linux-kernel - Re: [PATCH net-next v9 1/9] netmem: add niov->type attribute to distinguish different net

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAHS8izMZbt=NAK0GF6VqJNBRKy+iZQGMFG+jFJEesbz=5RiLXg@mail.gmail.com>
Date: Tue, 22 Apr 2025 13:46:24 -0700
From: Mina Almasry <almasrymina@...gle.com>
To: Pavel Begunkov <asml.silence@...il.com>
Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org, 
	linux-doc@...r.kernel.org, io-uring@...r.kernel.org, 
	virtualization@...ts.linux.dev, kvm@...r.kernel.org, 
	linux-kselftest@...r.kernel.org, "David S. Miller" <davem@...emloft.net>, 
	Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, 
	Simon Horman <horms@...nel.org>, Donald Hunter <donald.hunter@...il.com>, 
	Jonathan Corbet <corbet@....net>, Andrew Lunn <andrew+netdev@...n.ch>, 
	Jeroen de Borst <jeroendb@...gle.com>, Harshitha Ramamurthy <hramamurthy@...gle.com>, 
	Kuniyuki Iwashima <kuniyu@...zon.com>, Willem de Bruijn <willemb@...gle.com>, Jens Axboe <axboe@...nel.dk>, 
	David Ahern <dsahern@...nel.org>, Neal Cardwell <ncardwell@...gle.com>, 
	"Michael S. Tsirkin" <mst@...hat.com>, Jason Wang <jasowang@...hat.com>, 
	Xuan Zhuo <xuanzhuo@...ux.alibaba.com>, Eugenio Pérez <eperezma@...hat.com>, 
	Stefan Hajnoczi <stefanha@...hat.com>, Stefano Garzarella <sgarzare@...hat.com>, Shuah Khan <shuah@...nel.org>, 
	sdf@...ichev.me, dw@...idwei.uk, Jamal Hadi Salim <jhs@...atatu.com>, 
	Victor Nogueira <victor@...atatu.com>, Pedro Tammela <pctammela@...atatu.com>, 
	Samiullah Khawaja <skhawaja@...gle.com>
Subject: Re: [PATCH net-next v9 1/9] netmem: add niov->type attribute to
 distinguish different net_iov types

On Tue, Apr 22, 2025 at 12:52 PM Pavel Begunkov <asml.silence@...il.com> wrote:
>
> On 4/22/25 15:03, Mina Almasry wrote:
> > On Tue, Apr 22, 2025 at 1:16 AM Pavel Begunkov <asml.silence@...il.com> wrote:
> >>
> >> On 4/18/25 00:15, Mina Almasry wrote:
> >>> Later patches in the series adds TX net_iovs where there is no pp
> >>> associated, so we can't rely on niov->pp->mp_ops to tell what is the
> >>> type of the net_iov.
> >>
> >> That's fine, but that needs a NULL pp check in io_uring as well,
> >> specifically in io_zcrx_recv_frag().
> >>
> >
> > I think you mean this update in the code:
> >
> > if (!niov->pp || niov->pp->mp_ops != &io_uring_pp_zc_ops ||
> >      io_pp_to_ifq(niov->pp) != ifq)
> > return -EFAULT;
> >
> > Yes, thanks, will do.
>
> That will work. I'm assuming that those pp-less niovs can
> end up in the rx path. I think it was deemed not impossible,
> right?
>

I'm not sure these pp-less niovs can ever end up in the RX path, but
I'm not sure, and I guess better safe than sorry. We usually get
yelled at for defensive checks but I don't think this one is too
defensive. There could be a path where a TX skb somehow ends up here.

--
Thanks,
Mina