fix create_new_namespaces() return value

dup_mnt_ns() and clone_uts_ns() return NULL on failure.  This is wrong,
create_new_namespaces() uses ERR_PTR() to catch an error.  This means that the
subsequent create_new_namespaces() will hit BUG_ON() in copy_mnt_ns() or
copy_utsname().

Modify create_new_namespaces() to also use the errors returned by the
copy_*_ns routines and not to systematically return ENOMEM.

[oleg@tv-sign.ru: better changelog]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index c811a94e4c88..5585623f6252 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1451,7 +1451,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
 
         new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
         if (!new_ns)
-                return NULL;
+                return ERR_PTR(-ENOMEM);
 
         atomic_set(&new_ns->count, 1);
         INIT_LIST_HEAD(&new_ns->list);
@@ -1465,7 +1465,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
         if (!new_ns->root) {
                 up_write(&namespace_sem);
                 kfree(new_ns);
-                return NULL;
+                return ERR_PTR(-ENOMEM);;
         }
         spin_lock(&vfsmount_lock);
         list_add_tail(&new_ns->list, &new_ns->root->mnt_list);