userns: allow sethostname in a container

Changelog:
	Feb 23: let clone_uts_ns() handle setting uts->user_ns
		To do so we need to pass in the task_struct who'll
		get the utsname, so we can get its user_ns.
	Feb 23: As per Oleg's coment, just pass in tsk, instead of two
		of its members.

Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 6 deletions

diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c
index 034dc2ed13ac..b97fc9d04ddf 100644
--- a/kernel/nsproxy.c
+++ b/kernel/nsproxy.c
@@ -69,16 +69,11 @@ static struct nsproxy *create_new_namespaces(unsigned long flags,
                 goto out_ns;
         }
 
-        new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns);
+        new_nsp->uts_ns = copy_utsname(flags, tsk);
         if (IS_ERR(new_nsp->uts_ns)) {
                 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)) {