userns: add a user namespace owner of ipc ns

Changelog:
	Feb 15: Don't set new ipc->user_ns if we didn't create a new
		ipc_ns.
	Feb 23: Move extern declaration to ipc_namespace.h, and group
		fwd declarations at top.

Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Serge E. Hallyn 2011-03-23 16:43:23 -07:00 committed by Linus Torvalds
parent fc832ad364
commit b515498f5b
4 changed files with 16 additions and 2 deletions

View file

@ -15,6 +15,7 @@
#define IPCNS_CALLBACK_PRI 0
struct user_namespace;
struct ipc_ids {
int in_use;
@ -56,6 +57,8 @@ struct ipc_namespace {
unsigned int mq_msg_max; /* initialized to DFLT_MSGMAX */
unsigned int mq_msgsize_max; /* initialized to DFLT_MSGSIZEMAX */
/* user_ns which owns the ipc ns */
struct user_namespace *user_ns;
};
extern struct ipc_namespace init_ipc_ns;

View file

@ -32,6 +32,7 @@ struct ipc_namespace init_ipc_ns = {
.mq_msg_max = DFLT_MSGMAX,
.mq_msgsize_max = DFLT_MSGSIZEMAX,
#endif
.user_ns = &init_user_ns,
};
atomic_t nr_ipc_ns = ATOMIC_INIT(1);

View file

@ -11,10 +11,11 @@
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/user_namespace.h>
#include "util.h"
static struct ipc_namespace *create_ipc_ns(void)
static struct ipc_namespace *create_ipc_ns(struct ipc_namespace *old_ns)
{
struct ipc_namespace *ns;
int err;
@ -43,6 +44,9 @@ static struct ipc_namespace *create_ipc_ns(void)
ipcns_notify(IPCNS_CREATED);
register_ipcns_notifier(ns);
ns->user_ns = old_ns->user_ns;
get_user_ns(ns->user_ns);
return ns;
}
@ -50,7 +54,7 @@ struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns)
{
if (!(flags & CLONE_NEWIPC))
return get_ipc_ns(ns);
return create_ipc_ns();
return create_ipc_ns(ns);
}
/*
@ -105,6 +109,7 @@ static void free_ipc_ns(struct ipc_namespace *ns)
* order to have a correct value when recomputing msgmni.
*/
ipcns_notify(IPCNS_REMOVED);
put_user_ns(ns->user_ns);
}
/*

View file

@ -80,6 +80,11 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
err = PTR_ERR(new_nsp->ipc_ns);
goto out_ipc;
}
if (new_nsp->ipc_ns != tsk->nsproxy->ipc_ns) {
put_user_ns(new_nsp->ipc_ns->user_ns);
new_nsp->ipc_ns->user_ns = task_cred_xxx(tsk, user)->user_ns;
get_user_ns(new_nsp->ipc_ns->user_ns);
}
new_nsp->pid_ns = copy_pid_ns(flags, task_active_pid_ns(tsk));
if (IS_ERR(new_nsp->pid_ns)) {