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From: Kees Cook <keescook@chromium.org>
To: "Theodore Y. Ts'o" <tytso@mit.edu>
Cc: Topi Miettinen <toiwoton@gmail.com>,
	Luis Chamberlain <mcgrof@kernel.org>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"open list:FILESYSTEMS (VFS and infrastructure)" 
	<linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH] Allow restricting permissions in /proc/sys
Date: Tue, 12 Nov 2019 15:15:15 -0800	[thread overview]
Message-ID: <201911121514.DA3BEED0@keescook> (raw)
In-Reply-To: <20191103175648.GA4603@mit.edu>

On Sun, Nov 03, 2019 at 12:56:48PM -0500, Theodore Y. Ts'o wrote:
> On Sun, Nov 03, 2019 at 04:55:48PM +0200, Topi Miettinen wrote:
> > Several items in /proc/sys need not be accessible to unprivileged
> > tasks. Let the system administrator change the permissions, but only
> > to more restrictive modes than what the sysctl tables allow.
> > 
> > Signed-off-by: Topi Miettinen <toiwoton@gmail.com>
> 
> Why should restruct the system administrator from changing the
> permissions to one which is more lax than what the sysctl tables?
> 
> The system administrator is already very much trusted.  Why should we
> take that discretion away from the system administrator?

Generally speaking, they're there to provide some sense of boundary
between uid 0 and the kernel proper. I think it's correct to not allow
weakening of these permissions (which is the current state: no change at
all).

-- 
Kees Cook

  parent reply	other threads:[~2019-11-12 23:15 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-03 14:55 [PATCH] Allow restricting permissions in /proc/sys Topi Miettinen
2019-11-03 17:56 ` Theodore Y. Ts'o
2019-11-03 19:24   ` Topi Miettinen
2019-11-12 23:15   ` Kees Cook [this message]
2019-11-03 18:50 ` Eric W. Biederman
2019-11-03 19:38   ` Topi Miettinen
2019-11-04 15:44     ` Eric W. Biederman
2019-11-04 17:58       ` Topi Miettinen
2019-11-04 23:41         ` Eric W. Biederman
2019-11-05  7:35           ` Topi Miettinen
2019-11-12 23:19             ` Kees Cook
2019-11-13  1:04               ` Luis Chamberlain
2019-11-12 23:22 ` Christian Brauner
2019-11-13  4:50   ` Andy Lutomirski
2019-11-13 10:52     ` Topi Miettinen
2019-11-13 16:00   ` Jann Horn
2019-11-13 16:19     ` Topi Miettinen
2019-11-13 16:40       ` Jann Horn

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