Re: [PATCH] sysfs: Allow mounting without CONFIG_NET

[James Hogan <james.hogan@imgtec.com>]

On 23/09/13 22:41, Eric W. Biederman wrote:
> 
> In kobj_ns_current_may_mount the default should be to allow the
> mount.  The test is only for a single kobj_ns_type at a time, and unless
> there is a reason to prevent it the mounting sysfs should be allowed.
> Subsystems that are not registered can't have are not involved so can't
> have a reason to prevent mounting sysfs.
> 
> This is a bug-fix to:
>     commit 7dc5dbc879bd0779924b5132a48b731a0bc04a1e
>     Author: Eric W. Biederman <ebiederm@xmission.com>
>     Date:   Mon Mar 25 20:07:01 2013 -0700
>     
>         sysfs: Restrict mounting sysfs
>         
>         Don't allow mounting sysfs unless the caller has CAP_SYS_ADMIN rights
>         over the net namespace.  The principle here is if you create or have
>         capabilities over it you can mount it, otherwise you get to live with
>         what other people have mounted.
>         
>         Instead of testing this with a straight forward ns_capable call,
>         perform this check the long and torturous way with kobject helpers,
>         this keeps direct knowledge of namespaces out of sysfs, and preserves
>         the existing sysfs abstractions.
>         
>         Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>         Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
> 
> That came in via the userns tree during the 3.12 merge window.
>     
> Reported-by: James Hogan <james.hogan@imgtec.com>
> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

Tested-by: James Hogan <james.hogan@imgtec.com>

Thanks
James