linux-kernel - Re: NFS4 authentification / fsuid

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: <20070906150616.GA28565@fieldses.org>
Date:	Thu, 6 Sep 2007 11:06:16 -0400
From:	"J. Bruce Fields" <bfields@...ldses.org>
To:	Satyam Sharma <satyam@...radead.org>
Cc:	Trond Myklebust <trond.myklebust@....uio.no>,
	Jan Engelhardt <jengelh@...putergmbh.de>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: NFS4 authentification / fsuid

On Thu, Sep 06, 2007 at 01:44:05PM +0530, Satyam Sharma wrote:
> /dev/kmem was just an example -- IMHO differentiating between kernel and
> userspace from a security p.o.v. is always tricky.

The things that come to mind are /dev/kmem and module-loading.  What
else is there?  And what is it that makes this inherently difficult?

> Like Trond said, there are very high number of ways in which
> privileged userspace can compromise a running kernel if it really
> wants to do that, root-is-God has always been *the* major problem with
> Unix :-)
> 
> The only _real_ way a kernel can lock itself completely against
> malicious userspace involves trusted tamperproof hardware,

The question of how to protect against someone with *physical* access
certainly is more difficult, but surely that's a separate problem.

--b.
-
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/