1 files changed, 49 insertions, 4 deletions

diff --git a/ipc/namespace.c b/ipc/namespace.c
index a1094ff0befa..ce0a647869b1 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -11,10 +11,13 @@
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/mount.h>
+#include <linux/user_namespace.h>
+#include <linux/proc_fs.h>
 
 #include "util.h"
 
-static struct ipc_namespace *create_ipc_ns(void)
+static struct ipc_namespace *create_ipc_ns(struct task_struct *tsk,
+                                           struct ipc_namespace *old_ns)
 {
         struct ipc_namespace *ns;
         int err;
@@ -43,14 +46,19 @@ static struct ipc_namespace *create_ipc_ns(void)
         ipcns_notify(IPCNS_CREATED);
         register_ipcns_notifier(ns);
 
+        ns->user_ns = get_user_ns(task_cred_xxx(tsk, user)->user_ns);
+
         return ns;
 }
 
-struct ipc_namespace *copy_ipcs(unsigned long flags, struct ipc_namespace *ns)
+struct ipc_namespace *copy_ipcs(unsigned long flags,
+                                struct task_struct *tsk)
 {
+        struct ipc_namespace *ns = tsk->nsproxy->ipc_ns;
+
         if (!(flags & CLONE_NEWIPC))
                 return get_ipc_ns(ns);
-        return create_ipc_ns();
+        return create_ipc_ns(tsk, ns);
 }
 
 /*
@@ -97,7 +105,6 @@ static void free_ipc_ns(struct ipc_namespace *ns)
         sem_exit_ns(ns);
         msg_exit_ns(ns);
         shm_exit_ns(ns);
-        kfree(ns);
         atomic_dec(&nr_ipc_ns);
 
         /*
@@ -105,6 +112,8 @@ static void free_ipc_ns(struct ipc_namespace *ns)
          * order to have a correct value when recomputing msgmni.
          */
         ipcns_notify(IPCNS_REMOVED);
+        put_user_ns(ns->user_ns);
+        kfree(ns);
 }
 
 /*
@@ -132,3 +141,39 @@ void put_ipc_ns(struct ipc_namespace *ns)
                 free_ipc_ns(ns);
         }
 }
+
+static void *ipcns_get(struct task_struct *task)
+{
+        struct ipc_namespace *ns = NULL;
+        struct nsproxy *nsproxy;
+
+        rcu_read_lock();
+        nsproxy = task_nsproxy(task);
+        if (nsproxy)
+                ns = get_ipc_ns(nsproxy->ipc_ns);
+        rcu_read_unlock();
+
+        return ns;
+}
+
+static void ipcns_put(void *ns)
+{
+        return put_ipc_ns(ns);
+}
+
+static int ipcns_install(struct nsproxy *nsproxy, void *ns)
+{
+        /* Ditch state from the old ipc namespace */
+        exit_sem(current);
+        put_ipc_ns(nsproxy->ipc_ns);
+        nsproxy->ipc_ns = get_ipc_ns(ns);
+        return 0;
+}
+
+const struct proc_ns_operations ipcns_operations = {
+        .name           = "ipc",
+        .type           = CLONE_NEWIPC,
+        .get            = ipcns_get,
+        .put            = ipcns_put,
+        .install        = ipcns_install,
+};