3 files changed, 37 insertions, 16 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 1d0e9ea1fa05..741bbe42dfe8 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -399,11 +399,8 @@ void daemonize(const char *name, ...)
         current->fs = fs;
         atomic_inc(&fs->count);
 
-        exit_namespace(current);
         exit_task_namespaces(current);
-        current->namespace = init_task.namespace;
         current->nsproxy = init_task.nsproxy;
-        get_namespace(current->namespace);
         get_task_namespaces(current);
 
         exit_files(current);
@@ -923,7 +920,6 @@ fastcall NORET_TYPE void do_exit(long code)
         exit_sem(tsk);
         __exit_files(tsk);
         __exit_fs(tsk);
-        exit_namespace(tsk);
         exit_task_namespaces(tsk);
         exit_thread();
         cpuset_exit(tsk);
diff --git a/kernel/fork.c b/kernel/fork.c
index c9e660ae47aa..33fcf0733ca6 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1119,11 +1119,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                 goto bad_fork_cleanup_mm;
         if ((retval = copy_namespaces(clone_flags, p)))
                 goto bad_fork_cleanup_keys;
-        if ((retval = copy_namespace(clone_flags, p)))
-                goto bad_fork_cleanup_namespaces;
         retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
         if (retval)
-                goto bad_fork_cleanup_namespace;
+                goto bad_fork_cleanup_namespaces;
 
         p->set_child_tid = (clone_flags & CLONE_CHILD_SETTID) ? child_tidptr : NULL;
         /*
@@ -1215,7 +1213,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                 spin_unlock(&current->sighand->siglock);
                 write_unlock_irq(&tasklist_lock);
                 retval = -ERESTARTNOINTR;
-                goto bad_fork_cleanup_namespace;
+                goto bad_fork_cleanup_namespaces;
         }
 
         if (clone_flags & CLONE_THREAD) {
@@ -1263,8 +1261,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
         proc_fork_connector(p);
         return p;
 
-bad_fork_cleanup_namespace:
-        exit_namespace(p);
 bad_fork_cleanup_namespaces:
         exit_task_namespaces(p);
 bad_fork_cleanup_keys:
@@ -1519,10 +1515,9 @@ static int unshare_fs(unsigned long unshare_flags, struct fs_struct **new_fsp)
  */
 static int unshare_namespace(unsigned long unshare_flags, struct namespace **new_nsp, struct fs_struct *new_fs)
 {
-        struct namespace *ns = current->namespace;
+        struct namespace *ns = current->nsproxy->namespace;
 
-        if ((unshare_flags & CLONE_NEWNS) &&
-            (ns && atomic_read(&ns->count) > 1)) {
+        if ((unshare_flags & CLONE_NEWNS) && ns) {
                 if (!capable(CAP_SYS_ADMIN))
                         return -EPERM;
 
@@ -1655,8 +1650,8 @@ asmlinkage long sys_unshare(unsigned long unshare_flags)
                 }
 
                 if (new_ns) {
-                        ns = current->namespace;
-                        current->namespace = new_ns;
+                        ns = current->nsproxy->namespace;
+                        current->nsproxy->namespace = new_ns;
                         new_ns = ns;
                 }
 
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index a3612f82f187..e10385c17f73 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -13,6 +13,7 @@
 #include <linux/version.h>
 #include <linux/nsproxy.h>
 #include <linux/init_task.h>
+#include <linux/namespace.h>
 
 struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy);
 
@@ -55,6 +56,11 @@ struct nsproxy *dup_namespaces(struct nsproxy *orig)
 {
         struct nsproxy *ns = clone_namespaces(orig);
 
+        if (ns) {
+                if (ns->namespace)
+                        get_namespace(ns->namespace);
+        }
+
         return ns;
 }
 
@@ -65,16 +71,40 @@ struct nsproxy *dup_namespaces(struct nsproxy *orig)
 int copy_namespaces(int flags, struct task_struct *tsk)
 {
         struct nsproxy *old_ns = tsk->nsproxy;
+        struct nsproxy *new_ns;
+        int err = 0;
 
         if (!old_ns)
                 return 0;
 
         get_nsproxy(old_ns);
 
-        return 0;
+        if (!(flags & CLONE_NEWNS))
+                return 0;
+
+        new_ns = clone_namespaces(old_ns);
+        if (!new_ns) {
+                err = -ENOMEM;
+                goto out;
+        }
+
+        tsk->nsproxy = new_ns;
+
+        err = copy_namespace(flags, tsk);
+        if (err) {
+                tsk->nsproxy = old_ns;
+                put_nsproxy(new_ns);
+                goto out;
+        }
+
+out:
+        put_nsproxy(old_ns);
+        return err;
 }
 
 void free_nsproxy(struct nsproxy *ns)
 {
+                if (ns->namespace)
+                        put_namespace(ns->namespace);
                 kfree(ns);
 }