kernel-ark/include/linux/kobject_ns.h
Eric W. Biederman 7dc5dbc879 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>
2013-08-28 21:35:14 -07:00

61 lines
1.9 KiB
C

/* Kernel object name space definitions
*
* Copyright (c) 2002-2003 Patrick Mochel
* Copyright (c) 2002-2003 Open Source Development Labs
* Copyright (c) 2006-2008 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (c) 2006-2008 Novell Inc.
*
* Split from kobject.h by David Howells (dhowells@redhat.com)
*
* This file is released under the GPLv2.
*
* Please read Documentation/kobject.txt before using the kobject
* interface, ESPECIALLY the parts about reference counts and object
* destructors.
*/
#ifndef _LINUX_KOBJECT_NS_H
#define _LINUX_KOBJECT_NS_H
struct sock;
struct kobject;
/*
* Namespace types which are used to tag kobjects and sysfs entries.
* Network namespace will likely be the first.
*/
enum kobj_ns_type {
KOBJ_NS_TYPE_NONE = 0,
KOBJ_NS_TYPE_NET,
KOBJ_NS_TYPES
};
/*
* Callbacks so sysfs can determine namespaces
* @grab_current_ns: return a new reference to calling task's namespace
* @netlink_ns: return namespace to which a sock belongs (right?)
* @initial_ns: return the initial namespace (i.e. init_net_ns)
* @drop_ns: drops a reference to namespace
*/
struct kobj_ns_type_operations {
enum kobj_ns_type type;
bool (*current_may_mount)(void);
void *(*grab_current_ns)(void);
const void *(*netlink_ns)(struct sock *sk);
const void *(*initial_ns)(void);
void (*drop_ns)(void *);
};
int kobj_ns_type_register(const struct kobj_ns_type_operations *ops);
int kobj_ns_type_registered(enum kobj_ns_type type);
const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent);
const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj);
bool kobj_ns_current_may_mount(enum kobj_ns_type type);
void *kobj_ns_grab_current(enum kobj_ns_type type);
const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk);
const void *kobj_ns_initial(enum kobj_ns_type type);
void kobj_ns_drop(enum kobj_ns_type type, void *ns);
#endif /* _LINUX_KOBJECT_NS_H */