ipc: Initialize ipc_namespace->user_ns early.

Allow the ipc namespace initialization code to depend on ns->user_ns
being set during initialization.

In particular this allows mq_init_ns to use ns->user_ns for permission
checks and initializating s_user_ns while the the mq filesystem is
being mounted.

Acked-by: Seth Forshee <seth.forshee@canonical.com>
Suggested-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/ipc/namespace.c b/ipc/namespace.c
index 068caf18d565..04cb07eb81f1 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -34,8 +34,11 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
         ns->ns.ops = &ipcns_operations;
 
         atomic_set(&ns->count, 1);
+        ns->user_ns = get_user_ns(user_ns);
+
         err = mq_init_ns(ns);
         if (err) {
+                put_user_ns(ns->user_ns);
                 ns_free_inum(&ns->ns);
                 kfree(ns);
                 return ERR_PTR(err);
@@ -46,8 +49,6 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
         msg_init_ns(ns);
         shm_init_ns(ns);
 
-        ns->user_ns = get_user_ns(user_ns);
-
         return ns;
 }