From: asmadeus@codewreck.org
To: Kees Cook <kees@kernel.org>
Cc: Dominique Martinet via B4 Relay
<devnull+asmadeus.codewreck.org@kernel.org>,
Eric Van Hensbergen <ericvh@kernel.org>,
Latchesar Ionkov <lucho@ionkov.net>,
Christian Schoenebeck <linux_oss@crudebyte.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Michael Grzeschik <m.grzeschik@pengutronix.de>,
stable@vger.kernel.org, Yuhao Jiang <danisjiang@gmail.com>,
security@kernel.org, v9fs@lists.linux.dev,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] net/9p: Fix buffer overflow in USB transport layer
Date: Mon, 23 Jun 2025 05:39:29 +0900 [thread overview]
Message-ID: <aFhqAergj6LowmyE@codewreck.org> (raw)
In-Reply-To: <659844BA-48EF-47E1-8D66-D4CA98359BBF@kernel.org>
Kees Cook wrote on Sun, Jun 22, 2025 at 01:02:20PM -0700:
> >- p9_rx_req->rc.size = req->actual;
> >+ memcpy(p9_rx_req->rc.sdata, req->buf, req_size);
>
> Is rc.sdata always rc.capacity sized? If so, this world be a good first adopter of the __counted_by annotation for pointer struct members, available in Clang trunk and soon in GCC:
> https://gcc.gnu.org/pipermail/gcc-patches/2025-May/683696.html
I think so, I'll add the annotation in another patch when time allows
(and try to revert this commit to check it works, even if I have no
reason to believe it wouldn't catch this)
(... And this made me realize commit 60ece0833b6c ("net/9p: allocate
appropriate reduced message buffers") likely broke everything for
9p/rdma 3 years ago, as rdma is swapping buffers around...
I guess it doesn't have (m)any users...)
--
Dominique Martinet | Asmadeus
next prev parent reply other threads:[~2025-06-22 20:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-22 13:39 [PATCH v3] net/9p: Fix buffer overflow in USB transport layer Dominique Martinet via B4 Relay
2025-06-22 20:02 ` Kees Cook
2025-06-22 20:39 ` asmadeus [this message]
2025-06-22 21:20 ` Christian Schoenebeck
2025-06-22 21:37 ` asmadeus
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=aFhqAergj6LowmyE@codewreck.org \
--to=asmadeus@codewreck.org \
--cc=danisjiang@gmail.com \
--cc=devnull+asmadeus.codewreck.org@kernel.org \
--cc=ericvh@kernel.org \
--cc=gregkh@linuxfoundation.org \
--cc=kees@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux_oss@crudebyte.com \
--cc=lucho@ionkov.net \
--cc=m.grzeschik@pengutronix.de \
--cc=security@kernel.org \
--cc=stable@vger.kernel.org \
--cc=v9fs@lists.linux.dev \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox