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  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Mon, 20 Feb 2017 17:24:52 +1300
From: (Eric W. Biederman)
To:     James Bottomley <>
Cc:     Vivek Goyal <>,
        Amir Goldstein <>,
        Djalal Harouni <>, Chris Mason <>,
        Theodore Tso <>,
        Josh Triplett <>,
        Andy Lutomirski <>,
        Seth Forshee <>,
        linux-fsdevel <>,
        linux-kernel <>,
        LSM List <>,
        Dongsu Park <>,
        David Herrmann <>,
        Miklos Szeredi <>,
        Alban Crequy <>,
        Al Viro <>,
        "Serge E. Hallyn" <>, Phil Estes <>
Subject: Re: [RFC 1/1] shiftfs: uid/gid shifting bind mount

James Bottomley <> writes:

> On Fri, 2017-02-17 at 14:57 +1300, Eric W. Biederman wrote:
>> I think I am missing something but I completely do not understand 
>> that subthread that says use file marks and perform the work in the 
>> vfs. The problem is that fundamentally we need multiple mappings and 
>> I don't see a mark on a file (even an inherited mark) providing the 
>> mapping so I don't see the point.
> The point of the mark is that it's a statement by the system
> administrator that the underlying subtree is safe to be mounted by an
> unprivileged container in the containers user view (i.e. with
> current_user_ns() == s_user_ns).  For the unprivileged container
> there's no real arbitrary s_user_ns use case because the unprivileged
> container must prove it can set up the mapping, so it would likely
> always be mounting from within a user_ns with the mapping it wanted.

As a statement that it is ok for the unprivileged mapping code to
operate that seems reasonable.  I don't currently the need for such an
ok from the system adminstrator, but if you need it a flag that
propagates to children and child directories seems reasonable.


Powered by blists - more mailing lists