1 files changed, 42 insertions, 4 deletions

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index a05d191ffdd9..d6a00f3de15d 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -22,6 +22,9 @@
 #include <linux/pid_namespace.h>
 #include <net/net_namespace.h>
 #include <linux/ipc_namespace.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
+#include <linux/syscalls.h>
 
 static struct kmem_cache *nsproxy_cachep;
 
@@ -198,10 +201,6 @@ int unshare_nsproxy_namespaces(unsigned long unshare_flags,
 		goto out;
 	}
 
-	err = ns_cgroup_clone(current, task_pid(current));
-	if (err)
-		put_nsproxy(*new_nsp);
-
 out:
 	return err;
 }
@@ -233,6 +232,45 @@ void exit_task_namespaces(struct task_struct *p)
 	switch_task_namespaces(p, NULL);
 }
 
+SYSCALL_DEFINE2(setns, int, fd, int, nstype)
+{
+	const struct proc_ns_operations *ops;
+	struct task_struct *tsk = current;
+	struct nsproxy *new_nsproxy;
+	struct proc_inode *ei;
+	struct file *file;
+	int err;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	file = proc_ns_fget(fd);
+	if (IS_ERR(file))
+		return PTR_ERR(file);
+
+	err = -EINVAL;
+	ei = PROC_I(file->f_dentry->d_inode);
+	ops = ei->ns_ops;
+	if (nstype && (ops->type != nstype))
+		goto out;
+
+	new_nsproxy = create_new_namespaces(0, tsk, tsk->fs);
+	if (IS_ERR(new_nsproxy)) {
+		err = PTR_ERR(new_nsproxy);
+		goto out;
+	}
+
+	err = ops->install(new_nsproxy, ei->ns);
+	if (err) {
+		free_nsproxy(new_nsproxy);
+		goto out;
+	}
+	switch_task_namespaces(tsk, new_nsproxy);
+out:
+	fput(file);
+	return err;
+}
+
 static int __init nsproxy_cache_init(void)
 {
 	nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC);