From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
To: Luigi Semenzato <semenzato@google.com>
Cc: linux-mm@kvack.org
Subject: Re: security: restricting access to swap
Date: Tue, 12 Mar 2013 09:06:36 -0400 [thread overview]
Message-ID: <20130312130636.GC17901@phenom.dumpdata.com> (raw)
In-Reply-To: <CAA25o9RchY2AD8U30bh4H+fz6kq8bs98SUrkJUkTpbTHSGjcGA@mail.gmail.com>
On Mon, Mar 11, 2013 at 04:57:25PM -0700, Luigi Semenzato wrote:
> Greetings linux-mmers,
>
> before we can fully deploy zram, we must ensure it conforms to the
> Chrome OS security requirements. In particular, we do not want to
> allow user space to read/write the swap device---not even root-owned
> processes.
>
> A similar restriction is available for /dev/mem under CONFIG_STRICT_DEVMEM.
>
> There are a few possible approaches to this, but before we go ahead
> I'd like to ask if anything has happened or is planned in this
> direction.
>
> Otherwise, one idea I am playing with is to add a CONFIG_STRICT_SWAP
> option that would do this for any swap device (i.e. not specific to
> zram) and possibly also when swapping to a file. We would add an
> "internal" open flag, O_KERN_SWAP, as well as clean up a little bit
> the FMODE_NONOTIFY confusion by adding the kernel flag O_KERN_NONOTIFY
> and formalizing the sets of external (O_*) and internal (O_KERN_*)
> open flags.
>
> Swapon() and swapoff() would use O_KERN_SWAP internally, and a device
> opened with that flag would reject user-level opens.
What/who does the swapon/swapoff calls? Is there an kernel level thread
(aka init but in kernel?) that would do this?
>
> Thank you in advance for any input/suggestion!
> Luigi
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
>
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2013-03-12 13:06 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-11 23:57 security: restricting access to swap Luigi Semenzato
2013-03-12 13:06 ` Konrad Rzeszutek Wilk [this message]
2013-03-12 15:46 ` Luigi Semenzato
2013-03-12 23:32 ` Simon Jeons
2013-03-15 9:04 ` Ric Mason
2013-03-15 15:48 ` Luigi Semenzato
2013-03-15 16:55 ` Johannes Weiner
2013-03-15 17:27 ` Luigi Semenzato
2013-03-15 22:19 ` Luigi Semenzato
2013-03-18 3:58 ` Hugh Dickins
2013-03-18 16:05 ` Luigi Semenzato
2013-03-18 23:43 ` KOSAKI Motohiro
2013-03-19 17:39 ` Will Drewry
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=20130312130636.GC17901@phenom.dumpdata.com \
--to=konrad.wilk@oracle.com \
--cc=linux-mm@kvack.org \
--cc=semenzato@google.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;
as well as URLs for NNTP newsgroup(s).