5 files changed, 20 insertions, 2 deletions

diff --git a/include/linux/utsname.h b/include/linux/utsname.h
index 69f39974c041..2c3c0f543705 100644
--- a/include/linux/utsname.h
+++ b/include/linux/utsname.h
@@ -37,9 +37,13 @@ struct new_utsname {
 #include <linux/nsproxy.h>
 #include <linux/err.h>
 
+struct user_namespace;
+extern struct user_namespace init_user_ns;
+
 struct uts_namespace {
         struct kref kref;
         struct new_utsname name;
+        struct user_namespace *user_ns;
 };
 extern struct uts_namespace init_uts_ns;
 
diff --git a/init/version.c b/init/version.c
index adff586401a5..86fe0ccb997a 100644
--- a/init/version.c
+++ b/init/version.c
@@ -33,6 +33,7 @@ struct uts_namespace init_uts_ns = {
                 .machine        = UTS_MACHINE,
                 .domainname     = UTS_DOMAINNAME,
         },
+        .user_ns = &init_user_ns,
 };
 EXPORT_SYMBOL_GPL(init_uts_ns);
 
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index f74e6c00e26d..034dc2ed13ac 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -74,6 +74,11 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
                 err = PTR_ERR(new_nsp->uts_ns);
                 goto out_uts;
         }
+        if (new_nsp->uts_ns != tsk->nsproxy->uts_ns) {
+                put_user_ns(new_nsp->uts_ns->user_ns);
+                new_nsp->uts_ns->user_ns = task_cred_xxx(tsk, user)->user_ns;
+                get_user_ns(new_nsp->uts_ns->user_ns);
+        }
 
         new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns);
         if (IS_ERR(new_nsp->ipc_ns)) {
diff --git a/kernel/user.c b/kernel/user.c
index 5c598ca781df..9e03e9c1df8d 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -17,9 +17,13 @@
 #include <linux/module.h>
 #include <linux/user_namespace.h>
 
+/*
+ * userns count is 1 for root user, 1 for init_uts_ns,
+ * and 1 for... ?
+ */
 struct user_namespace init_user_ns = {
         .kref = {
-                .refcount       = ATOMIC_INIT(2),
+                .refcount       = ATOMIC_INIT(3),
         },
         .creator = &root_user,
 };
@@ -47,7 +51,7 @@ static struct kmem_cache *uid_cachep;
  */
 static DEFINE_SPINLOCK(uidhash_lock);
 
-/* root_user.__count is 2, 1 for init task cred, 1 for init_user_ns->creator */
+/* root_user.__count is 2, 1 for init task cred, 1 for init_user_ns->user_ns */
 struct user_struct root_user = {
         .__count        = ATOMIC_INIT(2),
         .processes      = ATOMIC_INIT(1),
diff --git a/kernel/utsname.c b/kernel/utsname.c
index 8a82b4b8ea52..a7b3a8d1ad24 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -14,6 +14,7 @@
 #include <linux/utsname.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/user_namespace.h>
 
 static struct uts_namespace *create_uts_ns(void)
 {
@@ -40,6 +41,8 @@ static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns)
 
         down_read(&uts_sem);
         memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
+        ns->user_ns = old_ns->user_ns;
+        get_user_ns(ns->user_ns);
         up_read(&uts_sem);
         return ns;
 }
@@ -71,5 +74,6 @@ void free_uts_ns(struct kref *kref)
         struct uts_namespace *ns;
 
         ns = container_of(kref, struct uts_namespace, kref);
+        put_user_ns(ns->user_ns);
         kfree(ns);
 }