To: serue@us.ibm.com
CC: miklos@szeredi.hu, akpm@linux-foundation.org, hch@infradead.org,
       serue@us.ibm.com, linux-fsdevel@vger.kernel.org,
       linux-kernel@vger.kernel.org
In-reply-to: <20080206202110.GA20528@sergelap.ibm.com> (serue@us.ibm.com)
Subject: Re: [patch 07/10] unprivileged mounts: add sysctl tunable for
	"safe" property
References: <20080205213616.343721693@szeredi.hu> <20080205213705.120219893@szeredi.hu> <20080206202110.GA20528@sergelap.ibm.com>
Message-Id: <E1JMrXw-0000qq-O9@pomaz-ex.szeredi.hu>
From: Miklos Szeredi <miklos@szeredi.hu>
Date: Wed, 06 Feb 2008 22:11:08 +0100
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 861
Lines: 23

> > +	t->table[0].mode = 0644;
> 
> Yikes, this could be a problem for containers, as it's simply tied to
> uid 0, whereas tying it to a capability would let us solve it with
> capability bounds.
> 
> This might mean more urgency to get user namespaces working at least
> with sysfs, else this is a quick way around having CAP_SYS_ADMIN taken
> out of a container's capability bounding set.

I think I understand the problem, but not the solution.  How do user
namespaces going to help?

Maybe sysctls just need to check capabilities, instead of uids.  I
think that would make a lot of sense anyway.

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