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>
diff --git a/kernel/utsname.c b/kernel/utsname.c
index a7b3a8d..4464617 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -31,7 +31,8 @@
* @old_ns: namespace to clone
* Return NULL on error (failure to kmalloc), new ns otherwise
*/
-static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns)
+static struct uts_namespace *clone_uts_ns(struct task_struct *tsk,
+ struct uts_namespace *old_ns)
{
struct uts_namespace *ns;
@@ -41,8 +42,7 @@
down_read(&uts_sem);
memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
- ns->user_ns = old_ns->user_ns;
- get_user_ns(ns->user_ns);
+ ns->user_ns = get_user_ns(task_cred_xxx(tsk, user)->user_ns);
up_read(&uts_sem);
return ns;
}
@@ -53,8 +53,10 @@
* utsname of this process won't be seen by parent, and vice
* versa.
*/
-struct uts_namespace *copy_utsname(unsigned long flags, struct uts_namespace *old_ns)
+struct uts_namespace *copy_utsname(unsigned long flags,
+ struct task_struct *tsk)
{
+ struct uts_namespace *old_ns = tsk->nsproxy->uts_ns;
struct uts_namespace *new_ns;
BUG_ON(!old_ns);
@@ -63,7 +65,7 @@
if (!(flags & CLONE_NEWUTS))
return old_ns;
- new_ns = clone_uts_ns(old_ns);
+ new_ns = clone_uts_ns(tsk, old_ns);
put_uts_ns(old_ns);
return new_ns;