Re: [PATCH v17 01/15] Add PR_{GET,SET}_NO_NEW_PRIVS to prevent execvefrom granting privs

From: Andrew Lutomirski
Date: Fri Apr 06 2012 - 16:54:42 EST


On Fri, Apr 6, 2012 at 1:47 PM, Markus Gutschke <markus@xxxxxxxxxxxx> wrote:
> On Fri, Apr 6, 2012 at 12:49, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>> On Thu, 29 Mar 2012 15:01:46 -0500
>> Will Drewry <wad@xxxxxxxxxxxx> wrote:
>>> From: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
>>> With this set, a lot of dangerous operations (chroot, unshare, etc)
>>> become a lot less dangerous because there is no possibility of
>>> subverting privileged binaries.
>
> I don't want to derail things. So, tell me to go away, if I can't have
> what I want.
>
> Having said that, it would be great if NO_NEW_PRIVS also gave access
> to the restricted clone() flags. Such as CLONE_NEWIPC, CLONE_NEWNET
> and CLONE_NEWPID.

I decided to hold off on extra controversy for awhile. However:

https://git.kernel.org/?p=linux/kernel/git/luto/linux.git;a=commit;h=9a520b74ad5dc14a3d6950b6d63a64714adbdd7d
and
http://web.mit.edu/luto/www/linux/nnp/newns.c

I fully intend to resurrect both of those once nnp lands.

(FWIW, I think that CLONE_NEWPID interacts badly with unix socket
credentials and should be fixed as a prerequisite for making it easier
to access.)

--Andy
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