From b515498f5bb5f38fc0e390b4ff7d00b6077de127 Mon Sep 17 00:00:00 2001
From: "Serge E. Hallyn" <serge@hallyn.com>
Date: Wed, 23 Mar 2011 16:43:23 -0700
Subject: [PATCH] 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>
---
include/linux/ipc_namespace.h | 3 +++
ipc/msgutil.c | 1 +
ipc/namespace.c | 9 +++++++--
kernel/nsproxy.c | 5 +++++
4 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 51952989ad426..d3c32dcec6239 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -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;
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index f095ee2688333..8b5ce5d3f3ef3 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -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);
diff --git a/ipc/namespace.c b/ipc/namespace.c
index a1094ff0befa2..aa1889962693d 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -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);
}
/*
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index b97fc9d04ddfe..ac8a56e90bf81 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -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)) {
--
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