From: Christoph Hellwig <hch@lst.de>
To: Kanchan Joshi <joshi.k@samsung.com>
Cc: Keith Busch <kbusch@kernel.org>, Christoph Hellwig <hch@lst.de>,
axboe@kernel.dk, sagi@grimberg.me,
linux-nvme@lists.infradead.org, vincentfu@gmail.com,
ankit.kumar@samsung.com, joshiiitr@gmail.com,
stable@vger.kernel.org, Vincent Fu <vincent.fu@samsung.com>
Subject: Re: [PATCH v4] nvme: fix corruption for passthrough meta/data
Date: Fri, 13 Oct 2023 17:47:08 +0200 [thread overview]
Message-ID: <20231013154708.GA17455@lst.de> (raw)
In-Reply-To: <3438f3b8-f7d4-f0bd-44ef-7efb09ed6151@samsung.com>
On Fri, Oct 13, 2023 at 08:41:54PM +0530, Kanchan Joshi wrote:
> It seems we will have two limitations with this approach - (i) sgl for
> the external metadata buffer, and (ii) using sgl for data-transfer will
> reduce the speed of passthrough io, perhaps more than what can happen
> using the checks. And if we make the sgl opt-in, that means leaving the
> hole for the case when this was not chosen.
The main limitation is that the device needs to support SGLs, and
we need to as well (we currently don't for metadata). But for any
non-stupid workload SGLs should be at least as fast if not faster
with modern hardware. But I see no way out.
Now can we please get a patch to disable the unprivileged passthrough
ASAP to fix this probably exploitable hole? Or should I write one?
next prev parent reply other threads:[~2023-10-13 15:47 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20231013052157epcas5p3dc0698c56f9846191d315fa8d33ccb5c@epcas5p3.samsung.com>
2023-10-13 5:14 ` [PATCH v4] nvme: fix corruption for passthrough meta/data Kanchan Joshi
2023-10-13 5:26 ` Christoph Hellwig
2023-10-13 5:37 ` Kanchan Joshi
2023-10-13 10:14 ` Kanchan Joshi
2023-10-13 12:59 ` Kanchan Joshi
2023-10-13 13:54 ` Keith Busch
2023-10-13 15:11 ` Kanchan Joshi
2023-10-13 15:47 ` Christoph Hellwig [this message]
2023-10-13 18:35 ` Kanchan Joshi
2023-10-16 18:29 ` Keith Busch
2023-10-16 18:34 ` Christoph Hellwig
2023-10-15 19:19 ` Kanchan Joshi
2023-10-16 5:46 ` Christoph Hellwig
2023-10-26 14:33 ` Kanchan Joshi
2023-10-26 15:08 ` Keith Busch
2023-10-27 7:09 ` Kanchan Joshi
2023-10-13 5:32 ` Kanchan Joshi
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=20231013154708.GA17455@lst.de \
--to=hch@lst.de \
--cc=ankit.kumar@samsung.com \
--cc=axboe@kernel.dk \
--cc=joshi.k@samsung.com \
--cc=joshiiitr@gmail.com \
--cc=kbusch@kernel.org \
--cc=linux-nvme@lists.infradead.org \
--cc=sagi@grimberg.me \
--cc=stable@vger.kernel.org \
--cc=vincent.fu@samsung.com \
--cc=vincentfu@gmail.com \
/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