KEYS: Use structure to capture key restriction function and data

Replace struct key's restrict_link function pointer with a pointer to
the new struct key_restriction. The structure contains pointers to the
restriction function as well as relevant data for evaluating the
restriction.

The garbage collector checks restrict_link->keytype when key types are
unregistered. Restrictions involving a removed key type are converted
to use restrict_link_reject so that restrictions cannot be removed by
unregistering key types.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>

1 files changed, 10 insertions, 1 deletions

diff --git a/security/integrity/ima/ima_mok.c b/security/integrity/ima/ima_mok.c
index 74a279957464..073ddc9bce5b 100644
--- a/security/integrity/ima/ima_mok.c
+++ b/security/integrity/ima/ima_mok.c
@@ -17,6 +17,7 @@
 #include <linux/cred.h>
 #include <linux/err.h>
 #include <linux/init.h>
+#include <linux/slab.h>
 #include <keys/system_keyring.h>
 
 
@@ -27,15 +28,23 @@ struct key *ima_blacklist_keyring;
  */
 __init int ima_mok_init(void)
 {
+	struct key_restriction *restriction;
+
 	pr_notice("Allocating IMA blacklist keyring.\n");
 
+	restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
+	if (!restriction)
+		panic("Can't allocate IMA blacklist restriction.");
+
+	restriction->check = restrict_link_by_builtin_trusted;
+
 	ima_blacklist_keyring = keyring_alloc(".ima_blacklist",
 				KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
 				(KEY_POS_ALL & ~KEY_POS_SETATTR) |
 				KEY_USR_VIEW | KEY_USR_READ |
 				KEY_USR_WRITE | KEY_USR_SEARCH,
 				KEY_ALLOC_NOT_IN_QUOTA,
-				restrict_link_by_builtin_trusted, NULL);
+				restriction, NULL);
 
 	if (IS_ERR(ima_blacklist_keyring))
 		panic("Can't allocate IMA blacklist keyring.");