[PATCH 2/3] keys: consider user namespace in key_permission

["Serge E. Hallyn" <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>]

If a key is owned by another user namespace, then treat the
key as though it is owned by both another uid and gid.

Signed-off-by: Serge E. Hallyn <serue-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
---
 security/keys/permission.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/security/keys/permission.c b/security/keys/permission.c
index 5d9fc7b..0ed802c 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -35,6 +35,9 @@ int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
 
 	key = key_ref_to_ptr(key_ref);
 
+	if (key->user->user_ns != cred->user->user_ns)
+		goto use_other_perms;
+
 	/* use the second 8-bits of permissions for keys the caller owns */
 	if (key->uid == cred->fsuid) {
 		kperm = key->perm >> 16;
@@ -56,6 +59,8 @@ int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
 		}
 	}
 
+use_other_perms:
+
 	/* otherwise use the least-significant 8-bits */
 	kperm = key->perm;
 
-- 
1.5.4.3