linux-kernel - Re: [PATCH review 12/16] userns: For /proc/self/{uid, gid}_map derive the lower userns from the struct file

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 19 Nov 2012 13:27:45 -0800
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	Serge Hallyn <serge.hallyn@...onical.com>
Cc:	Linux Containers <containers@...ts.linux-foundation.org>,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH review 12/16] userns: For /proc/self/{uid, gid}_map derive the lower userns from the struct file

Serge Hallyn <serge.hallyn@...onical.com> writes:

> Quoting Eric W. Biederman (ebiederm@...ssion.com):
>> 
>> In practice when playing around it is the difference between.
>> unshare -U /bin/bash
>> echo 0 1000 1 > /proc/self/uid_map
>> 
>> And the need to pre-plan something.  You can set the uid_map from the
>> parent in a shell script but it is a real pain.  So for just messing
>> around allowing seq_ns == ns is a real advantage.
>
> Heh, ok - I almost always want >1 uid mapped, but I can see the
> advantage.

The original plan called for an upcall and >1 uid mapped.  But yeah
that is something else again.

> Thanks.
>
> I don't recall whether I put this in originally, but
>
> Acked-by: Serge E. Hallyn <serge.hallyn@...ntu.com>
>
>> > I also wonder if -EINVAL would be a more appropriate choice here.
>> > We're trying to keep things sane, rather than saying "not allowed"
>> > for its own sake.
>> 
>> A different error code might be better.
>
> I suppose strictly speaking (looking at errno-base.h) it would be
> EBADF?

Definitely not EBADF.  EBADF is the error code for operating on a closed
file descriptor.

I want a ENOTALLOWED. Anyway.

Eric

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