Re: [PATCH 2/2] user_namespaces.7: Update the documention to reflect the fixes for negative groups

["Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>]

On 02/11/2015 03:01 PM, Eric W. Biederman wrote:
> "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> writes:
> 
>> Hi Eric,
>>
>> Ping!
>>
>> Cheers,
>>
>> Michael
>>
>>
>> On 2 February 2015 at 16:37, Michael Kerrisk (man-pages)
>> <mtk.manpages@gmail.com> wrote:
>>> Hi Eric,
>>>
>>> Thanks for writing this up!
>>>
>>> On 12/12/2014 10:54 PM, Eric W. Biederman wrote:
>>>>
>>>> Files with access permissions such as ---rwx---rwx give fewer
>>>> permissions to their group then they do to everyone else.  Which means
>>>> dropping groups with setgroups(0, NULL) actually grants a process
>>>> privileges.
>>>>
>>>> The uprivileged setting of gid_map turned out not to be safe after
>         ^^^^^^^^^^^
> unprivileged  -- typo fix

Thanks for confirming.

>>>> this change.  Privilege setting of gid_map can be interpreted as
>>>> meaning yes it is ok to drop groups.
>>>
>>> I had trouble to parse that sentence (and I'd like to make sure that
>>> the right sentence ends up in the commit message). Did you mean:
>>>
>>>     "*Unprivileged* setting of gid_map can be interpreted as meaning
>>>      yes it is ok to drop groups"
>>> ?
>>>
>>> Or something else?
> 
> 
> I meant:  Setting of gid_map with privilege has been clarified to mean
> that dropping groups is ok.  This allows existing programs that set
> gid_map with privilege to work without changes.  That is newgidmap
> continues to work unchanged.

Thanks. I added that text to the changelog message.

Cheers,

Michael



-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/