1 files changed, 38 insertions, 16 deletions

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 88292e3dee96..a9ab8affc092 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -1,6 +1,6 @@
-/* keyring.c: keyring handling
+/* Keyring handling
  *
- * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-2005, 2008 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -79,7 +79,7 @@ static DECLARE_RWSEM(keyring_serialise_link_sem);
  * publish the name of a keyring so that it can be found by name (if it has
  * one)
  */
-void keyring_publish_name(struct key *keyring)
+static void keyring_publish_name(struct key *keyring)
 {
         int bucket;
 
@@ -292,7 +292,7 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref,
 
         struct keyring_list *keylist;
         struct timespec now;
-        unsigned long possessed;
+        unsigned long possessed, kflags;
         struct key *keyring, *key;
         key_ref_t key_ref;
         long err;
@@ -319,6 +319,32 @@ key_ref_t keyring_search_aux(key_ref_t keyring_ref,
         err = -EAGAIN;
         sp = 0;
 
+        /* firstly we should check to see if this top-level keyring is what we
+         * are looking for */
+        key_ref = ERR_PTR(-EAGAIN);
+        kflags = keyring->flags;
+        if (keyring->type == type && match(keyring, description)) {
+                key = keyring;
+
+                /* check it isn't negative and hasn't expired or been
+                 * revoked */
+                if (kflags & (1 << KEY_FLAG_REVOKED))
+                        goto error_2;
+                if (key->expiry && now.tv_sec >= key->expiry)
+                        goto error_2;
+                key_ref = ERR_PTR(-ENOKEY);
+                if (kflags & (1 << KEY_FLAG_NEGATIVE))
+                        goto error_2;
+                goto found;
+        }
+
+        /* otherwise, the top keyring must not be revoked, expired, or
+         * negatively instantiated if we are to search it */
+        key_ref = ERR_PTR(-EAGAIN);
+        if (kflags & ((1 << KEY_FLAG_REVOKED) | (1 << KEY_FLAG_NEGATIVE)) ||
+            (keyring->expiry && now.tv_sec >= keyring->expiry))
+                goto error_2;
+
         /* start processing a new keyring */
 descend:
         if (test_bit(KEY_FLAG_REVOKED, &keyring->flags))
@@ -331,13 +357,14 @@ descend:
         /* iterate through the keys in this keyring first */
         for (kix = 0; kix < keylist->nkeys; kix++) {
                 key = keylist->keys[kix];
+                kflags = key->flags;
 
                 /* ignore keys not of this type */
                 if (key->type != type)
                         continue;
 
                 /* skip revoked keys and expired keys */
-                if (test_bit(KEY_FLAG_REVOKED, &key->flags))
+                if (kflags & (1 << KEY_FLAG_REVOKED))
                         continue;
 
                 if (key->expiry && now.tv_sec >= key->expiry)
@@ -352,8 +379,8 @@ descend:
                                         context, KEY_SEARCH) < 0)
                         continue;
 
-                /* we set a different error code if we find a negative key */
-                if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
+                /* we set a different error code if we pass a negative key */
+                if (kflags & (1 << KEY_FLAG_NEGATIVE)) {
                         err = -ENOKEY;
                         continue;
                 }
@@ -489,10 +516,9 @@ key_ref_t __keyring_search_one(key_ref_t keyring_ref,
 /*
  * find a keyring with the specified name
  * - all named keyrings are searched
- * - only find keyrings with search permission for the process
- * - only find keyrings with a serial number greater than the one specified
+ * - normally only finds keyrings with search permission for the current process
  */
-struct key *find_keyring_by_name(const char *name, key_serial_t bound)
+struct key *find_keyring_by_name(const char *name, bool skip_perm_check)
 {
         struct key *keyring;
         int bucket;
@@ -518,15 +544,11 @@ struct key *find_keyring_by_name(const char *name, key_serial_t bound)
                         if (strcmp(keyring->description, name) != 0)
                                 continue;
 
-                        if (key_permission(make_key_ref(keyring, 0),
+                        if (!skip_perm_check &&
+                            key_permission(make_key_ref(keyring, 0),
                                            KEY_SEARCH) < 0)
                                 continue;
 
-                        /* found a potential candidate, but we still need to
-                         * check the serial number */
-                        if (keyring->serial <= bound)
-                                continue;
-
                         /* we've got a match */
                         atomic_inc(&keyring->usage);
                         read_unlock(&keyring_name_lock);