From: John Johansen <john.johansen-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>
To: Miklos Szeredi <miklos-sUDqSbJrdHQHWmgEVkV9KA@public.gmane.org>
Cc: linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
apparmor-nLRlyDuq1AZFpShjVBNYrg@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
draht-IBi9RG/b67k@public.gmane.org
Subject: Re: security_path hooks for xattr
Date: Thu, 26 Jan 2012 13:57:20 -0800 [thread overview]
Message-ID: <4F21CC40.3030207@canonical.com> (raw)
In-Reply-To: <87fwf2y6mw.fsf-d8RdFUjzFsbxNFs70CDYszOMxtEWgIxa@public.gmane.org>
On 01/26/2012 04:45 AM, Miklos Szeredi wrote:
> Forwarding from an internal bug report:
>
> "AppArmor does not mediate the xattr system calls for confined processes.
>
> As a consequence, a confined process can cross the confinement privilege
> boundary by reading or writing to extended attributes that the confined
> task should not have access to. The restrictions for security and user
> attributes read and write still apply according to DAC; however, this
> does not comply with the claim of AppArmor to mediate fipe
> operations. The use of extended attributes is very flexible, so that the
> effect of a missing mediation can lead to false assumptions in
> subsequent policy decisions (eCryptfs)."
>
> AFAIU this boils down to missing security hooks in *xattr().
>
> Would it be possible to add these hooks?
>
right, this is something we lost when we moved to the security_path hooks and
while we have spent some time looking at the problem, we haven't addressed it
yet.
New hooks would certainly be the easiest solution. I looked at it back when
I initially did the port, and considered proposing new hooks at the time, but
for various reasons it was decided to separate that from the main apparmor
submission, and I haven't had a chance to revisit this since.
--
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prev parent reply other threads:[~2012-01-26 21:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-26 12:45 security_path hooks for xattr Miklos Szeredi
[not found] ` <87fwf2y6mw.fsf-d8RdFUjzFsbxNFs70CDYszOMxtEWgIxa@public.gmane.org>
2012-01-26 16:04 ` Casey Schaufler
2012-01-26 21:57 ` John Johansen [this message]
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