userns: Allow unprivileged use of setns.
- Push the permission check from the core setns syscall into
the setns install methods where the user namespace of the
target namespace can be determined, and used in a ns_capable
call.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/ipc/namespace.c b/ipc/namespace.c
index f362298c..6ed33c0 100644
--- a/ipc/namespace.c
+++ b/ipc/namespace.c
@@ -161,8 +161,12 @@
return put_ipc_ns(ns);
}
-static int ipcns_install(struct nsproxy *nsproxy, void *ns)
+static int ipcns_install(struct nsproxy *nsproxy, void *new)
{
+ struct ipc_namespace *ns = new;
+ if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN))
+ return -EPERM;
+
/* Ditch state from the old ipc namespace */
exit_sem(current);
put_ipc_ns(nsproxy->ipc_ns);