1 files changed, 38 insertions, 45 deletions

diff --git a/security/keys/permission.c b/security/keys/permission.c
index 0ed802c9e69..732cc0beffd 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -1,4 +1,4 @@
-/* permission.c: key permission determination
+/* Key permission checking
  *
  * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
@@ -13,21 +13,22 @@
 #include <linux/security.h>
 #include "internal.h"
 
-/*****************************************************************************/
 /**
  * key_task_permission - Check a key can be used
- * @key_ref: The key to check
- * @cred: The credentials to use
- * @perm: The permissions to check for
+ * @key_ref: The key to check.
+ * @cred: The credentials to use.
+ * @perm: The permissions to check for.
  *
  * Check to see whether permission is granted to use a key in the desired way,
  * but permit the security modules to override.
  *
- * The caller must hold either a ref on cred or must hold the RCU readlock or a
- * spinlock.
+ * The caller must hold either a ref on cred or must hold the RCU readlock.
+ *
+ * Returns 0 if successful, -EACCES if access is denied based on the
+ * permissions bits or the LSM check.
  */
 int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
-			key_perm_t perm)
+			unsigned perm)
 {
 	struct key *key;
 	key_perm_t kperm;
@@ -35,19 +36,16 @@ 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) {
+	if (uid_eq(key->uid, cred->fsuid)) {
 		kperm = key->perm >> 16;
 		goto use_these_perms;
 	}
 
 	/* use the third 8-bits of permissions for keys the caller has a group
 	 * membership in common with */
-	if (key->gid != -1 && key->perm & KEY_GRP_ALL) {
-		if (key->gid == cred->fsgid) {
+	if (gid_valid(key->gid) && key->perm & KEY_GRP_ALL) {
+		if (gid_eq(key->gid, cred->fsgid)) {
 			kperm = key->perm >> 8;
 			goto use_these_perms;
 		}
@@ -59,8 +57,6 @@ 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;
 
@@ -72,46 +68,43 @@ use_these_perms:
 	if (is_key_possessed(key_ref))
 		kperm |= key->perm >> 24;
 
-	kperm = kperm & perm & KEY_ALL;
+	kperm = kperm & perm & KEY_NEED_ALL;
 
 	if (kperm != perm)
 		return -EACCES;
 
 	/* let LSM be the final arbiter */
 	return security_key_permission(key_ref, cred, perm);
-
-} /* end key_task_permission() */
-
+}
 EXPORT_SYMBOL(key_task_permission);
 
-/*****************************************************************************/
-/*
- * validate a key
+/**
+ * key_validate - Validate a key.
+ * @key: The key to be validated.
+ *
+ * Check that a key is valid, returning 0 if the key is okay, -ENOKEY if the
+ * key is invalidated, -EKEYREVOKED if the key's type has been removed or if
+ * the key has been revoked or -EKEYEXPIRED if the key has expired.
  */
-int key_validate(struct key *key)
+int key_validate(const struct key *key)
 {
-	struct timespec now;
-	int ret = 0;
-
-	if (key) {
-		/* check it's still accessible */
-		ret = -EKEYREVOKED;
-		if (test_bit(KEY_FLAG_REVOKED, &key->flags) ||
-		    test_bit(KEY_FLAG_DEAD, &key->flags))
-			goto error;
-
-		/* check it hasn't expired */
-		ret = 0;
-		if (key->expiry) {
-			now = current_kernel_time();
-			if (now.tv_sec >= key->expiry)
-				ret = -EKEYEXPIRED;
-		}
-	}
+	unsigned long flags = key->flags;
 
- error:
-	return ret;
+	if (flags & (1 << KEY_FLAG_INVALIDATED))
+		return -ENOKEY;
 
-} /* end key_validate() */
+	/* check it's still accessible */
+	if (flags & ((1 << KEY_FLAG_REVOKED) |
+		     (1 << KEY_FLAG_DEAD)))
+		return -EKEYREVOKED;
+
+	/* check it hasn't expired */
+	if (key->expiry) {
+		struct timespec now = current_kernel_time();
+		if (now.tv_sec >= key->expiry)
+			return -EKEYEXPIRED;
+	}
 
+	return 0;
+}
 EXPORT_SYMBOL(key_validate);