[PATCH] Keys: Possessor permissions should be additive
This patch makes the possessor permissions on a key additive with
user/group/other permissions on the same key.
This permits extra rights to be granted to the possessor of a key without
taking away any rights conferred by them owning the key or having common group
membership.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/security/keys/permission.c b/security/keys/permission.c
index 1c36516..03db073 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -27,12 +27,6 @@
key = key_ref_to_ptr(key_ref);
- /* use the top 8-bits of permissions for keys the caller possesses */
- if (is_key_possessed(key_ref)) {
- kperm = key->perm >> 24;
- goto use_these_perms;
- }
-
/* use the second 8-bits of permissions for keys the caller owns */
if (key->uid == context->fsuid) {
kperm = key->perm >> 16;
@@ -61,6 +55,12 @@
kperm = key->perm;
use_these_perms:
+ /* use the top 8-bits of permissions for keys the caller possesses
+ * - possessor permissions are additive with other permissions
+ */
+ if (is_key_possessed(key_ref))
+ kperm |= key->perm >> 24;
+
kperm = kperm & perm & KEY_ALL;
return kperm == perm;