linux-kernel - Re: security_path hooks for xattr

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] [day] [month] [year] [list]

Message-ID: <4F21CC40.3030207@canonical.com>
Date:	Thu, 26 Jan 2012 13:57:20 -0800
From:	John Johansen <john.johansen@...onical.com>
To:	Miklos Szeredi <miklos@...redi.hu>
CC:	apparmor@...ts.ubuntu.com, linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org, draht@...e.com
Subject: Re: security_path hooks for xattr

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.

--
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/