Merge tag 'keys-devel-20131210' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull misc keyrings fixes from David Howells:
 "These break down into five sets:

   - A patch to error handling in the big_key type for huge payloads.
     If the payload is larger than the "low limit" and the backing store
     allocation fails, then big_key_instantiate() doesn't clear the
     payload pointers in the key, assuming them to have been previously
     cleared - but only one of them is.

     Unfortunately, the garbage collector still calls big_key_destroy()
     when sees one of the pointers with a weird value in it (and not
     NULL) which it then tries to clean up.

   - Three patches to fix the keyring type:

     * A patch to fix the hash function to correctly divide keyrings off
       from keys in the topology of the tree inside the associative
       array.  This is only a problem if searching through nested
       keyrings - and only if the hash function incorrectly puts the a
       keyring outside of the 0 branch of the root node.

     * A patch to fix keyrings' use of the associative array.  The
       __key_link_begin() function initially passes a NULL key pointer
       to assoc_array_insert() on the basis that it's holding a place in
       the tree whilst it does more allocation and stuff.

       This is only a problem when a node contains 16 keys that match at
       that level and we want to add an also matching 17th.  This should
       easily be manufactured with a keyring full of keyrings (without
       chucking any other sort of key into the mix) - except for (a)
       above which makes it on average adding the 65th keyring.

     * A patch to fix searching down through nested keyrings, where any
       keyring in the set has more than 16 keyrings and none of the
       first keyrings we look through has a match (before the tree
       iteration needs to step to a more distal node).

     Test in keyutils test suite:

        http://git.kernel.org/cgit/linux/kernel/git/dhowells/keyutils.git/commit/?id=8b4ae963ed92523aea18dfbb8cab3f4979e13bd1

   - A patch to fix the big_key type's use of a shmem file as its
     backing store causing audit messages and LSM check failures.  This
     is done by setting S_PRIVATE on the file to avoid LSM checks on the
     file (access to the shmem file goes through the keyctl() interface
     and so is gated by the LSM that way).

     This isn't normally a problem if a key is used by the context that
     generated it - and it's currently only used by libkrb5.

     Test in keyutils test suite:

        http://git.kernel.org/cgit/linux/kernel/git/dhowells/keyutils.git/commit/?id=d9a53cbab42c293962f2f78f7190253fc73bd32e

   - A patch to add a generated file to .gitignore.

   - A patch to fix the alignment of the system certificate data such
     that it it works on s390.  As I understand it, on the S390 arch,
     symbols must be 2-byte aligned because loading the address discards
     the least-significant bit"

* tag 'keys-devel-20131210' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  KEYS: correct alignment of system_certificate_list content in assembly file
  Ignore generated file kernel/x509_certificate_list
  security: shmem: implement kernel private shmem inodes
  KEYS: Fix searching of nested keyrings
  KEYS: Fix multiple key add into associative array
  KEYS: Fix the keyring hash function
  KEYS: Pre-clear struct key on allocation

1 files changed, 8 insertions, 9 deletions

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 69f0cb7bab7e..d46cbc5e335e 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -160,7 +160,7 @@ static u64 mult_64x32_and_fold(u64 x, u32 y)
 static unsigned long hash_key_type_and_desc(const struct keyring_index_key *index_key)
 {
 	const unsigned level_shift = ASSOC_ARRAY_LEVEL_STEP;
-	const unsigned long level_mask = ASSOC_ARRAY_LEVEL_STEP_MASK;
+	const unsigned long fan_mask = ASSOC_ARRAY_FAN_MASK;
 	const char *description = index_key->description;
 	unsigned long hash, type;
 	u32 piece;
@@ -194,10 +194,10 @@ static unsigned long hash_key_type_and_desc(const struct keyring_index_key *inde
 	 * ordinary keys by making sure the lowest level segment in the hash is
 	 * zero for keyrings and non-zero otherwise.
 	 */
-	if (index_key->type != &key_type_keyring && (hash & level_mask) == 0)
+	if (index_key->type != &key_type_keyring && (hash & fan_mask) == 0)
 		return hash | (hash >> (ASSOC_ARRAY_KEY_CHUNK_SIZE - level_shift)) | 1;
-	if (index_key->type == &key_type_keyring && (hash & level_mask) != 0)
-		return (hash + (hash << level_shift)) & ~level_mask;
+	if (index_key->type == &key_type_keyring && (hash & fan_mask) != 0)
+		return (hash + (hash << level_shift)) & ~fan_mask;
 	return hash;
 }
 
@@ -279,12 +279,11 @@ static bool keyring_compare_object(const void *object, const void *data)
  * Compare the index keys of a pair of objects and determine the bit position
  * at which they differ - if they differ.
  */
-static int keyring_diff_objects(const void *_a, const void *_b)
+static int keyring_diff_objects(const void *object, const void *data)
 {
-	const struct key *key_a = keyring_ptr_to_key(_a);
-	const struct key *key_b = keyring_ptr_to_key(_b);
+	const struct key *key_a = keyring_ptr_to_key(object);
 	const struct keyring_index_key *a = &key_a->index_key;
-	const struct keyring_index_key *b = &key_b->index_key;
+	const struct keyring_index_key *b = data;
 	unsigned long seg_a, seg_b;
 	int level, i;
 
@@ -691,8 +690,8 @@ descend_to_node:
 		smp_read_barrier_depends();
 		ptr = ACCESS_ONCE(shortcut->next_node);
 		BUG_ON(!assoc_array_ptr_is_node(ptr));
-		node = assoc_array_ptr_to_node(ptr);
 	}
+	node = assoc_array_ptr_to_node(ptr);
 
 begin_node:
 	kdebug("begin_node");