linux-kernel - Re: Why not make kdbus use CUSE?

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: <20141202172612.GA8958@kroah.com>
Date:	Tue, 2 Dec 2014 09:26:12 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	Richard Yao <ryao@...too.org>
Cc:	linux-kernel@...r.kernel.org, linux-api@...r.kernel.org
Subject: Re: Why not make kdbus use CUSE?

On Tue, Dec 02, 2014 at 07:22:11AM -0500, Richard Yao wrote:
> Assuming that this dance succeeds, the FUSE process could then make a
> readonly file in itself, open it read only, unlink it, put the data into
> the file and send the file descriptor via UNIX domain socket while
> refusing further writes. If it has its own user/group, the file should
> be safe from prying eyes.
> 
> This is not as good as a memfd and also suffers from the race that
> O_TMPFILE was meant to close, but it should be able to function as a
> decent fallback.

We can't knowingly create and advocate for broken code, sorry.

> This would preserve portability across not only
> different versions of Linux, but also other POSIX systems.

I honestly do not care about any other system than Linux, so I don't see
why this would ever be an issue.

> Keeping the code in userspace would allow us to apply SELinux policies
> to it, which is something that we would lose if it were go to into the
> kernel.

On the contrary, the kdbusfs implementation gives you better security
model support than before, it ties directly into the LSM hooks, see the
add-on patches from some other developers that bring full support of LSM
to the codebase.

> That said, it is still not clear to me that dbus must be inside the
> kernel to be able to perform multicast and zero copy using memfd.

It seems you have yet to read my introductory email for the patch
series.

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/