1 files changed, 8 insertions, 17 deletions

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 8e7811086b82..49746c81ad8d 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -204,20 +204,13 @@ void switch_task_namespaces(struct task_struct *p, struct nsproxy *new)
 
         might_sleep();
 
+        task_lock(p);
         ns = p->nsproxy;
+        p->nsproxy = new;
+        task_unlock(p);
 
-        rcu_assign_pointer(p->nsproxy, new);
-
-        if (ns && atomic_dec_and_test(&ns->count)) {
-                /*
-                 * wait for others to get what they want from this nsproxy.
-                 *
-                 * cannot release this nsproxy via the call_rcu() since
-                 * put_mnt_ns() will want to sleep
-                 */
-                synchronize_rcu();
+        if (ns && atomic_dec_and_test(&ns->count))
                 free_nsproxy(ns);
-        }
 }
 
 void exit_task_namespaces(struct task_struct *p)
@@ -227,11 +220,10 @@ void exit_task_namespaces(struct task_struct *p)
 
 SYSCALL_DEFINE2(setns, int, fd, int, nstype)
 {
-        const struct proc_ns_operations *ops;
         struct task_struct *tsk = current;
         struct nsproxy *new_nsproxy;
-        struct proc_ns *ei;
         struct file *file;
+        struct ns_common *ns;
         int err;
 
         file = proc_ns_fget(fd);
@@ -239,9 +231,8 @@ SYSCALL_DEFINE2(setns, int, fd, int, nstype)
                 return PTR_ERR(file);
 
         err = -EINVAL;
-        ei = get_proc_ns(file_inode(file));
-        ops = ei->ns_ops;
-        if (nstype && (ops->type != nstype))
+        ns = get_proc_ns(file_inode(file));
+        if (nstype && (ns->ops->type != nstype))
                 goto out;
 
         new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs);
@@ -250,7 +241,7 @@ SYSCALL_DEFINE2(setns, int, fd, int, nstype)
                 goto out;
         }
 
-        err = ops->install(new_nsproxy, ei->ns);
+        err = ns->ops->install(new_nsproxy, ns);
         if (err) {
                 free_nsproxy(new_nsproxy);
                 goto out;