Re: [PATCH] sysfs: Allow mounting without CONFIG_NET

From: James Hogan
Date: Tue Sep 24 2013 - 07:27:18 EST

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@xxxxxxxxxxxx>
> 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@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
> That came in via the userns tree during the 3.12 merge window.
> Reported-by: James Hogan <james.hogan@xxxxxxxxxx>
> Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>

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


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