From: Christoph Hellwig <hch@lst.de>
To: Kanchan Joshi <joshiiitr@gmail.com>
Cc: Keith Busch <kbusch@kernel.org>, Christoph Hellwig <hch@lst.de>,
Kanchan Joshi <joshi.k@samsung.com>,
axboe@kernel.dk, sagi@grimberg.me,
linux-nvme@lists.infradead.org, vincentfu@gmail.com,
ankit.kumar@samsung.com, cpgs@samsung.com,
stable@vger.kernel.org, Vincent Fu <vincent.fu@samsung.com>
Subject: Re: [PATCH v3] nvme: fix memory corruption for passthrough metadata
Date: Fri, 13 Oct 2023 06:38:06 +0200 [thread overview]
Message-ID: <20231013043806.GA5797@lst.de> (raw)
In-Reply-To: <CA+1E3r+gEPQgaieuwNXuXSDp5LHCQpUa8KFc80za4L9e88bUhg@mail.gmail.com>
On Fri, Oct 13, 2023 at 07:49:19AM +0530, Kanchan Joshi wrote:
> > precedent to start doing it.
> In my mind, this was about dealing with the specific case when the
> kernel memory is being used for device DMA.
> We have just two cases: (i) separate meta buffer, and (ii) bounce
> buffer for data (+metadata).
> I had not planned sanity checks for user inputs for anything beyond that.
> As opposed to being preventive (in all cases), it was about failing
> only when we are certain that DMA will take place and it will corrupt
> kernel memory.
>
> In the long-term, it may be possible for the path to do away with
> memory copies. The checks can disappear with that.
As soon as the user buffer is unaligned we need to bounce buffer,
including for the data buffer.
next prev parent reply other threads:[~2023-10-13 4:38 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20231006135322epcas5p1c9acf38b04f35017181c715c706281dc@epcas5p1.samsung.com>
2023-10-06 13:47 ` [PATCH v3] nvme: fix memory corruption for passthrough metadata Kanchan Joshi
2023-10-10 7:46 ` Christoph Hellwig
2023-10-10 13:39 ` Kanchan Joshi
2023-10-10 15:31 ` Clay Mayers
2023-10-11 5:03 ` Christoph Hellwig
2023-10-11 5:02 ` Christoph Hellwig
2023-10-11 5:26 ` Kanchan Joshi
2023-10-11 6:36 ` Christoph Hellwig
2023-10-11 17:04 ` Keith Busch
2023-10-12 4:36 ` Christoph Hellwig
2023-10-12 15:31 ` Keith Busch
2023-10-12 15:46 ` Christoph Hellwig
2023-10-13 2:19 ` Kanchan Joshi
2023-10-13 4:38 ` Christoph Hellwig [this message]
2023-10-13 5:50 ` 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=20231013043806.GA5797@lst.de \
--to=hch@lst.de \
--cc=ankit.kumar@samsung.com \
--cc=axboe@kernel.dk \
--cc=cpgs@samsung.com \
--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