lkml.org 
[lkml]   [2010]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Upstream first policy
From
Date

Weird. Somehow I only got a copy of this from lkml.

Alan Cox <alan@lxorguk.ukuu.org.uk> writes:

>> time. If pathnames were not fundamentally important we could apply
>> a patch like the one below and allow unprivileged users to unshare
>> the mount namespace and mount filesystems wherever. There is nothing
>> fundamental about those operations that require root privileges except
>> that you are manipulating the pathnames of objects.
>
> And in a purely SELinux enviromnment your patch would work out because
> you could use labels to control this stuff.
>
>
>> - if (!capable(CAP_SYS_ADMIN))
>> - return -EPERM;
>> -
>
> It does raise the question about whether you can do it if you had a
> namespace property of "ignore suidness". I'm not sure thats enough
> however.

The long term plan is to change that to.

if (nscapable(mnt_ns->user_ns, CAP_SYS_ADMIN))
return -EPERM.

That is.
- Create a new user/credential namespace (ultimately an unprivileged operation).
- Have the root user of the new user namespace create a new mount namespace.
- Over that new mount namespace the root user of the new user namespace
has full control.

It is a little convoluted but it maintains backwards compatibility. Unfortunately
there is still a long ways to go before we get there.

Eric


\
 
 \ /
  Last update: 2010-03-11 04:55    [W:0.117 / U:0.680 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site