2 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index c667255d70db..731edaca8ffd 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -26,6 +26,7 @@
 #define CLONE_STOPPED           0x02000000      /* Start in stopped state */
 #define CLONE_NEWUTS            0x04000000      /* New utsname group? */
 #define CLONE_NEWIPC            0x08000000      /* New ipcs */
+#define CLONE_NEWUSER           0x10000000      /* New user namespace */
 
 /*
  * Scheduling policies
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index 92a45867ecfb..bb320573bb9e 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -4,6 +4,7 @@
 #include <linux/kref.h>
 #include <linux/nsproxy.h>
 #include <linux/sched.h>
+#include <linux/err.h>
 
 #define UIDHASH_BITS    (CONFIG_BASE_SMALL ? 3 : 8)
 #define UIDHASH_SZ      (1 << UIDHASH_BITS)
@@ -45,6 +46,9 @@ static inline struct user_namespace *get_user_ns(struct user_namespace *ns)
 static inline struct user_namespace *copy_user_ns(int flags,
                                                   struct user_namespace *old_ns)
 {
+        if (flags & CLONE_NEWUSER)
+                return ERR_PTR(-EINVAL);
+
         return NULL;
 }