13 files changed, 396 insertions, 266 deletions

diff --git a/security/keys/Makefile b/security/keys/Makefile
index b34cc6ee6900..a56f1ffdc64d 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -14,7 +14,7 @@ obj-y := \
 	user_defined.o
 
 obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
-obj-$(CONFIG_ENCRYPTED_KEYS) += ecryptfs_format.o encrypted.o
+obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted-keys/
 obj-$(CONFIG_KEYS_COMPAT) += compat.o
 obj-$(CONFIG_PROC_FS) += proc.o
 obj-$(CONFIG_SYSCTL) += sysctl.o
diff --git a/security/keys/encrypted-keys/Makefile b/security/keys/encrypted-keys/Makefile
new file mode 100644
index 000000000000..6bc7a86d1027
--- /dev/null
+++ b/security/keys/encrypted-keys/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for encrypted keys
+#
+
+obj-$(CONFIG_ENCRYPTED_KEYS) += encrypted.o ecryptfs_format.o
+obj-$(CONFIG_TRUSTED_KEYS) += masterkey_trusted.o
diff --git a/security/keys/ecryptfs_format.c b/security/keys/encrypted-keys/ecryptfs_format.c
index 6daa3b6ff9ed..6daa3b6ff9ed 100644
--- a/security/keys/ecryptfs_format.c
+++ b/security/keys/encrypted-keys/ecryptfs_format.c
diff --git a/security/keys/ecryptfs_format.h b/security/keys/encrypted-keys/ecryptfs_format.h
index 40294de238bb..40294de238bb 100644
--- a/security/keys/ecryptfs_format.h
+++ b/security/keys/encrypted-keys/ecryptfs_format.h
diff --git a/security/keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index e7eca9ec4c65..f33804c1b4c8 100644
--- a/security/keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -299,31 +299,6 @@ out:
 }
 
 /*
- * request_trusted_key - request the trusted key
- *
- * Trusted keys are sealed to PCRs and other metadata. Although userspace
- * manages both trusted/encrypted key-types, like the encrypted key type
- * data, trusted key type data is not visible decrypted from userspace.
- */
-static struct key *request_trusted_key(const char *trusted_desc,
-				       u8 **master_key, size_t *master_keylen)
-{
-	struct trusted_key_payload *tpayload;
-	struct key *tkey;
-
-	tkey = request_key(&key_type_trusted, trusted_desc, NULL);
-	if (IS_ERR(tkey))
-		goto error;
-
-	down_read(&tkey->sem);
-	tpayload = rcu_dereference(tkey->payload.data);
-	*master_key = tpayload->key;
-	*master_keylen = tpayload->key_len;
-error:
-	return tkey;
-}
-
-/*
  * request_user_key - request the user key
  *
  * Use a user provided key to encrypt/decrypt an encrypted-key.
@@ -469,8 +444,14 @@ static struct key *request_master_key(struct encrypted_key_payload *epayload,
 		goto out;
 
 	if (IS_ERR(mkey)) {
-		pr_info("encrypted_key: key %s not found",
-			epayload->master_desc);
+		int ret = PTR_ERR(epayload);
+
+		if (ret == -ENOTSUPP)
+			pr_info("encrypted_key: key %s not supported",
+				epayload->master_desc);
+		else
+			pr_info("encrypted_key: key %s not found",
+				epayload->master_desc);
 		goto out;
 	}
 
@@ -686,11 +667,19 @@ static int encrypted_key_decrypt(struct encrypted_key_payload *epayload,
 		return -EINVAL;
 
 	hex_encoded_data = hex_encoded_iv + (2 * ivsize) + 2;
-	hex2bin(epayload->iv, hex_encoded_iv, ivsize);
-	hex2bin(epayload->encrypted_data, hex_encoded_data, encrypted_datalen);
+	ret = hex2bin(epayload->iv, hex_encoded_iv, ivsize);
+	if (ret < 0)
+		return -EINVAL;
+	ret = hex2bin(epayload->encrypted_data, hex_encoded_data,
+		      encrypted_datalen);
+	if (ret < 0)
+		return -EINVAL;
 
 	hmac = epayload->format + epayload->datablob_len;
-	hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2), HASH_SIZE);
+	ret = hex2bin(hmac, hex_encoded_data + (encrypted_datalen * 2),
+		      HASH_SIZE);
+	if (ret < 0)
+		return -EINVAL;
 
 	mkey = request_master_key(epayload, &master_key, &master_keylen);
 	if (IS_ERR(mkey))
diff --git a/security/keys/encrypted.h b/security/keys/encrypted-keys/encrypted.h
index cef5e2f2b7d1..b6ade8945250 100644
--- a/security/keys/encrypted.h
+++ b/security/keys/encrypted-keys/encrypted.h
@@ -2,6 +2,17 @@
 #define __ENCRYPTED_KEY_H
 
 #define ENCRYPTED_DEBUG 0
+#ifdef CONFIG_TRUSTED_KEYS
+extern struct key *request_trusted_key(const char *trusted_desc,
+				       u8 **master_key, size_t *master_keylen);
+#else
+static inline struct key *request_trusted_key(const char *trusted_desc,
+					      u8 **master_key,
+					      size_t *master_keylen)
+{
+	return ERR_PTR(-EOPNOTSUPP);
+}
+#endif
 
 #if ENCRYPTED_DEBUG
 static inline void dump_master_key(const u8 *master_key, size_t master_keylen)
diff --git a/security/keys/encrypted-keys/masterkey_trusted.c b/security/keys/encrypted-keys/masterkey_trusted.c
new file mode 100644
index 000000000000..df87272e3f51
--- /dev/null
+++ b/security/keys/encrypted-keys/masterkey_trusted.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright (C) 2010 IBM Corporation
+ * Copyright (C) 2010 Politecnico di Torino, Italy
+ *                    TORSEC group -- http://security.polito.it
+ *
+ * Authors:
+ * Mimi Zohar <zohar@us.ibm.com>
+ * Roberto Sassu <roberto.sassu@polito.it>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * See Documentation/security/keys-trusted-encrypted.txt
+ */
+
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <keys/trusted-type.h>
+
+/*
+ * request_trusted_key - request the trusted key
+ *
+ * Trusted keys are sealed to PCRs and other metadata. Although userspace
+ * manages both trusted/encrypted key-types, like the encrypted key type
+ * data, trusted key type data is not visible decrypted from userspace.
+ */
+struct key *request_trusted_key(const char *trusted_desc,
+				u8 **master_key, size_t *master_keylen)
+{
+	struct trusted_key_payload *tpayload;
+	struct key *tkey;
+
+	tkey = request_key(&key_type_trusted, trusted_desc, NULL);
+	if (IS_ERR(tkey))
+		goto error;
+
+	down_read(&tkey->sem);
+	tpayload = rcu_dereference(tkey->payload.data);
+	*master_key = tpayload->key;
+	*master_keylen = tpayload->key_len;
+error:
+	return tkey;
+}
diff --git a/security/keys/gc.c b/security/keys/gc.c
index 89df6b5f203c..bf4d8da5a795 100644
--- a/security/keys/gc.c
+++ b/security/keys/gc.c
@@ -1,6 +1,6 @@
 /* Key garbage collector
  *
- * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2009-2011 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -10,6 +10,8 @@
  */
 
 #include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/security.h>
 #include <keys/keyring-type.h>
 #include "internal.h"
 
@@ -19,17 +21,33 @@
 unsigned key_gc_delay = 5 * 60;
 
 /*
- * Reaper
+ * Reaper for unused keys.
+ */
+static void key_garbage_collector(struct work_struct *work);
+DECLARE_WORK(key_gc_work, key_garbage_collector);
+
+/*
+ * Reaper for links from keyrings to dead keys.
  */
 static void key_gc_timer_func(unsigned long);
-static void key_garbage_collector(struct work_struct *);
 static DEFINE_TIMER(key_gc_timer, key_gc_timer_func, 0, 0);
-static DECLARE_WORK(key_gc_work, key_garbage_collector);
-static key_serial_t key_gc_cursor; /* the last key the gc considered */
-static bool key_gc_again;
-static unsigned long key_gc_executing;
+
 static time_t key_gc_next_run = LONG_MAX;
-static time_t key_gc_new_timer;
+static struct key_type *key_gc_dead_keytype;
+
+static unsigned long key_gc_flags;
+#define KEY_GC_KEY_EXPIRED	0	/* A key expired and needs unlinking */
+#define KEY_GC_REAP_KEYTYPE	1	/* A keytype is being unregistered */
+#define KEY_GC_REAPING_KEYTYPE	2	/* Cleared when keytype reaped */
+
+
+/*
+ * Any key whose type gets unregistered will be re-typed to this if it can't be
+ * immediately unlinked.
+ */
+struct key_type key_type_dead = {
+	.name = "dead",
+};
 
 /*
  * Schedule a garbage collection run.
@@ -42,31 +60,75 @@ void key_schedule_gc(time_t gc_at)
 
 	kenter("%ld", gc_at - now);
 
-	if (gc_at <= now) {
-		schedule_work(&key_gc_work);
+	if (gc_at <= now || test_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags)) {
+		kdebug("IMMEDIATE");
+		queue_work(system_nrt_wq, &key_gc_work);
 	} else if (gc_at < key_gc_next_run) {
+		kdebug("DEFERRED");
+		key_gc_next_run = gc_at;
 		expires = jiffies + (gc_at - now) * HZ;
 		mod_timer(&key_gc_timer, expires);
 	}
 }
 
 /*
- * The garbage collector timer kicked off
+ * Some key's cleanup time was met after it expired, so we need to get the
+ * reaper to go through a cycle finding expired keys.
  */
 static void key_gc_timer_func(unsigned long data)
 {
 	kenter("");
 	key_gc_next_run = LONG_MAX;
-	schedule_work(&key_gc_work);
+	set_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags);
+	queue_work(system_nrt_wq, &key_gc_work);
+}
+
+/*
+ * wait_on_bit() sleep function for uninterruptible waiting
+ */
+static int key_gc_wait_bit(void *flags)
+{
+	schedule();
+	return 0;
+}
+
+/*
+ * Reap keys of dead type.
+ *
+ * We use three flags to make sure we see three complete cycles of the garbage
+ * collector: the first to mark keys of that type as being dead, the second to
+ * collect dead links and the third to clean up the dead keys.  We have to be
+ * careful as there may already be a cycle in progress.
+ *
+ * The caller must be holding key_types_sem.
+ */
+void key_gc_keytype(struct key_type *ktype)
+{
+	kenter("%s", ktype->name);
+
+	key_gc_dead_keytype = ktype;
+	set_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags);
+	smp_mb();
+	set_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags);
+
+	kdebug("schedule");
+	queue_work(system_nrt_wq, &key_gc_work);
+
+	kdebug("sleep");
+	wait_on_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE, key_gc_wait_bit,
+		    TASK_UNINTERRUPTIBLE);
+
+	key_gc_dead_keytype = NULL;
+	kleave("");
 }
 
 /*
  * Garbage collect pointers from a keyring.
  *
- * Return true if we altered the keyring.
+ * Not called with any locks held.  The keyring's key struct will not be
+ * deallocated under us as only our caller may deallocate it.
  */
-static bool key_gc_keyring(struct key *keyring, time_t limit)
-	__releases(key_serial_lock)
+static void key_gc_keyring(struct key *keyring, time_t limit)
 {
 	struct keyring_list *klist;
 	struct key *key;
@@ -93,130 +155,234 @@ static bool key_gc_keyring(struct key *keyring, time_t limit)
 unlock_dont_gc:
 	rcu_read_unlock();
 dont_gc:
-	kleave(" = false");
-	return false;
+	kleave(" [no gc]");
+	return;
 
 do_gc:
 	rcu_read_unlock();
-	key_gc_cursor = keyring->serial;
-	key_get(keyring);
-	spin_unlock(&key_serial_lock);
+
 	keyring_gc(keyring, limit);
-	key_put(keyring);
-	kleave(" = true");
-	return true;
+	kleave(" [gc]");
 }
 
 /*
- * Garbage collector for keys.  This involves scanning the keyrings for dead,
- * expired and revoked keys that have overstayed their welcome
+ * Garbage collect an unreferenced, detached key
  */
-static void key_garbage_collector(struct work_struct *work)
+static noinline void key_gc_unused_key(struct key *key)
 {
-	struct rb_node *rb;
-	key_serial_t cursor;
-	struct key *key, *xkey;
-	time_t new_timer = LONG_MAX, limit, now;
-
-	now = current_kernel_time().tv_sec;
-	kenter("[%x,%ld]", key_gc_cursor, key_gc_new_timer - now);
-
-	if (test_and_set_bit(0, &key_gc_executing)) {
-		key_schedule_gc(current_kernel_time().tv_sec + 1);
-		kleave(" [busy; deferring]");
-		return;
+	key_check(key);
+
+	security_key_free(key);
+
+	/* deal with the user's key tracking and quota */
+	if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
+		spin_lock(&key->user->lock);
+		key->user->qnkeys--;
+		key->user->qnbytes -= key->quotalen;
+		spin_unlock(&key->user->lock);
 	}
 
-	limit = now;
+	atomic_dec(&key->user->nkeys);
+	if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
+		atomic_dec(&key->user->nikeys);
+
+	key_user_put(key->user);
+
+	/* now throw away the key memory */
+	if (key->type->destroy)
+		key->type->destroy(key);
+
+	kfree(key->description);
+
+#ifdef KEY_DEBUGGING
+	key->magic = KEY_DEBUG_MAGIC_X;
+#endif
+	kmem_cache_free(key_jar, key);
+}
+
+/*
+ * Garbage collector for unused keys.
+ *
+ * This is done in process context so that we don't have to disable interrupts
+ * all over the place.  key_put() schedules this rather than trying to do the
+ * cleanup itself, which means key_put() doesn't have to sleep.
+ */
+static void key_garbage_collector(struct work_struct *work)
+{
+	static u8 gc_state;		/* Internal persistent state */
+#define KEY_GC_REAP_AGAIN	0x01	/* - Need another cycle */
+#define KEY_GC_REAPING_LINKS	0x02	/* - We need to reap links */
+#define KEY_GC_SET_TIMER	0x04	/* - We need to restart the timer */
+#define KEY_GC_REAPING_DEAD_1	0x10	/* - We need to mark dead keys */
+#define KEY_GC_REAPING_DEAD_2	0x20	/* - We need to reap dead key links */
+#define KEY_GC_REAPING_DEAD_3	0x40	/* - We need to reap dead keys */
+#define KEY_GC_FOUND_DEAD_KEY	0x80	/* - We found at least one dead key */
+
+	struct rb_node *cursor;
+	struct key *key;
+	time_t new_timer, limit;
+
+	kenter("[%lx,%x]", key_gc_flags, gc_state);
+
+	limit = current_kernel_time().tv_sec;
 	if (limit > key_gc_delay)
 		limit -= key_gc_delay;
 	else
 		limit = key_gc_delay;
 
+	/* Work out what we're going to be doing in this pass */
+	gc_state &= KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2;
+	gc_state <<= 1;
+	if (test_and_clear_bit(KEY_GC_KEY_EXPIRED, &key_gc_flags))
+		gc_state |= KEY_GC_REAPING_LINKS | KEY_GC_SET_TIMER;
+
+	if (test_and_clear_bit(KEY_GC_REAP_KEYTYPE, &key_gc_flags))
+		gc_state |= KEY_GC_REAPING_DEAD_1;
+	kdebug("new pass %x", gc_state);
+
+	new_timer = LONG_MAX;
+
+	/* As only this function is permitted to remove things from the key
+	 * serial tree, if cursor is non-NULL then it will always point to a
+	 * valid node in the tree - even if lock got dropped.
+	 */
 	spin_lock(&key_serial_lock);
+	cursor = rb_first(&key_serial_tree);
 
-	if (unlikely(RB_EMPTY_ROOT(&key_serial_tree))) {
-		spin_unlock(&key_serial_lock);
-		clear_bit(0, &key_gc_executing);
-		return;
-	}
+continue_scanning:
+	while (cursor) {
+		key = rb_entry(cursor, struct key, serial_node);
+		cursor = rb_next(cursor);
 
-	cursor = key_gc_cursor;
-	if (cursor < 0)
-		cursor = 0;
-	if (cursor > 0)
-		new_timer = key_gc_new_timer;
-	else
-		key_gc_again = false;
-
-	/* find the first key above the cursor */
-	key = NULL;
-	rb = key_serial_tree.rb_node;
-	while (rb) {
-		xkey = rb_entry(rb, struct key, serial_node);
-		if (cursor < xkey->serial) {
-			key = xkey;
-			rb = rb->rb_left;
-		} else if (cursor > xkey->serial) {
-			rb = rb->rb_right;
-		} else {
-			rb = rb_next(rb);
-			if (!rb)
-				goto reached_the_end;
-			key = rb_entry(rb, struct key, serial_node);
-			break;
+		if (atomic_read(&key->usage) == 0)
+			goto found_unreferenced_key;
+
+		if (unlikely(gc_state & KEY_GC_REAPING_DEAD_1)) {
+			if (key->type == key_gc_dead_keytype) {
+				gc_state |= KEY_GC_FOUND_DEAD_KEY;
+				set_bit(KEY_FLAG_DEAD, &key->flags);
+				key->perm = 0;
+				goto skip_dead_key;
+			}
+		}
+
+		if (gc_state & KEY_GC_SET_TIMER) {
+			if (key->expiry > limit && key->expiry < new_timer) {
+				kdebug("will expire %x in %ld",
+				       key_serial(key), key->expiry - limit);
+				new_timer = key->expiry;
+			}
 		}
-	}
 
-	if (!key)
-		goto reached_the_end;
+		if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2))
+			if (key->type == key_gc_dead_keytype)
+				gc_state |= KEY_GC_FOUND_DEAD_KEY;
 
-	/* trawl through the keys looking for keyrings */
-	for (;;) {
-		if (key->expiry > limit && key->expiry < new_timer) {
-			kdebug("will expire %x in %ld",
-			       key_serial(key), key->expiry - limit);
-			new_timer = key->expiry;
+		if ((gc_state & KEY_GC_REAPING_LINKS) ||
+		    unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) {
+			if (key->type == &key_type_keyring)
+				goto found_keyring;
 		}
 
-		if (key->type == &key_type_keyring &&
-		    key_gc_keyring(key, limit))
-			/* the gc had to release our lock so that the keyring
-			 * could be modified, so we have to get it again */
-			goto gc_released_our_lock;
+		if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3))
+			if (key->type == key_gc_dead_keytype)
+				goto destroy_dead_key;
 
-		rb = rb_next(&key->serial_node);
-		if (!rb)
-			goto reached_the_end;
-		key = rb_entry(rb, struct key, serial_node);
+	skip_dead_key:
+		if (spin_is_contended(&key_serial_lock) || need_resched())
+			goto contended;
 	}
 
-gc_released_our_lock:
-	kdebug("gc_released_our_lock");
-	key_gc_new_timer = new_timer;
-	key_gc_again = true;
-	clear_bit(0, &key_gc_executing);
-	schedule_work(&key_gc_work);
-	kleave(" [continue]");
-	return;
-
-	/* when we reach the end of the run, we set the timer for the next one */
-reached_the_end:
-	kdebug("reached_the_end");
+contended:
 	spin_unlock(&key_serial_lock);
-	key_gc_new_timer = new_timer;
-	key_gc_cursor = 0;
-	clear_bit(0, &key_gc_executing);
-
-	if (key_gc_again) {
-		/* there may have been a key that expired whilst we were
-		 * scanning, so if we discarded any links we should do another
-		 * scan */
-		new_timer = now + 1;
-		key_schedule_gc(new_timer);
-	} else if (new_timer < LONG_MAX) {
+
+maybe_resched:
+	if (cursor) {
+		cond_resched();
+		spin_lock(&key_serial_lock);
+		goto continue_scanning;
+	}
+
+	/* We've completed the pass.  Set the timer if we need to and queue a
+	 * new cycle if necessary.  We keep executing cycles until we find one
+	 * where we didn't reap any keys.
+	 */
+	kdebug("pass complete");
+
+	if (gc_state & KEY_GC_SET_TIMER && new_timer != (time_t)LONG_MAX) {
 		new_timer += key_gc_delay;
 		key_schedule_gc(new_timer);
 	}
-	kleave(" [end]");
+
+	if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) {
+		/* Make sure everyone revalidates their keys if we marked a
+		 * bunch as being dead and make sure all keyring ex-payloads
+		 * are destroyed.
+		 */
+		kdebug("dead sync");
+		synchronize_rcu();
+	}
+
+	if (unlikely(gc_state & (KEY_GC_REAPING_DEAD_1 |
+				 KEY_GC_REAPING_DEAD_2))) {
+		if (!(gc_state & KEY_GC_FOUND_DEAD_KEY)) {
+			/* No remaining dead keys: short circuit the remaining
+			 * keytype reap cycles.
+			 */
+			kdebug("dead short");
+			gc_state &= ~(KEY_GC_REAPING_DEAD_1 | KEY_GC_REAPING_DEAD_2);
+			gc_state |= KEY_GC_REAPING_DEAD_3;
+		} else {
+			gc_state |= KEY_GC_REAP_AGAIN;
+		}
+	}
+
+	if (unlikely(gc_state & KEY_GC_REAPING_DEAD_3)) {
+		kdebug("dead wake");
+		smp_mb();
+		clear_bit(KEY_GC_REAPING_KEYTYPE, &key_gc_flags);
+		wake_up_bit(&key_gc_flags, KEY_GC_REAPING_KEYTYPE);
+	}
+
+	if (gc_state & KEY_GC_REAP_AGAIN)
+		queue_work(system_nrt_wq, &key_gc_work);
+	kleave(" [end %x]", gc_state);
+	return;
+
+	/* We found an unreferenced key - once we've removed it from the tree,
+	 * we can safely drop the lock.
+	 */
+found_unreferenced_key:
+	kdebug("unrefd key %d", key->serial);
+	rb_erase(&key->serial_node, &key_serial_tree);
+	spin_unlock(&key_serial_lock);
+
+	key_gc_unused_key(key);
+	gc_state |= KEY_GC_REAP_AGAIN;
+	goto maybe_resched;
+
+	/* We found a keyring and we need to check the payload for links to
+	 * dead or expired keys.  We don't flag another reap immediately as we
+	 * have to wait for the old payload to be destroyed by RCU before we
+	 * can reap the keys to which it refers.
+	 */
+found_keyring:
+	spin_unlock(&key_serial_lock);
+	kdebug("scan keyring %d", key->serial);
+	key_gc_keyring(key, limit);
+	goto maybe_resched;
+
+	/* We found a dead key that is still referenced.  Reset its type and
+	 * destroy its payload with its semaphore held.
+	 */
+destroy_dead_key:
+	spin_unlock(&key_serial_lock);
+	kdebug("destroy key %d", key->serial);
+	down_write(&key->sem);
+	key->type = &key_type_dead;
+	if (key_gc_dead_keytype->destroy)
+		key_gc_dead_keytype->destroy(key);
+	memset(&key->payload, KEY_DESTROY, sizeof(key->payload));
+	up_write(&key->sem);
+	goto maybe_resched;
 }
diff --git a/security/keys/internal.h b/security/keys/internal.h
index f375152a2500..c7a7caec4830 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -31,6 +31,7 @@
 	no_printk(KERN_DEBUG FMT"\n", ##__VA_ARGS__)
 #endif
 
+extern struct key_type key_type_dead;
 extern struct key_type key_type_user;
 
 /*****************************************************************************/
@@ -75,6 +76,7 @@ extern unsigned key_quota_maxbytes;
 #define KEYQUOTA_LINK_BYTES	4		/* a link in a keyring is worth 4 bytes */
 
 
+extern struct kmem_cache *key_jar;
 extern struct rb_root key_serial_tree;
 extern spinlock_t key_serial_lock;
 extern struct mutex key_construction_mutex;
@@ -146,9 +148,11 @@ extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
 
 extern long join_session_keyring(const char *name);
 
+extern struct work_struct key_gc_work;
 extern unsigned key_gc_delay;
 extern void keyring_gc(struct key *keyring, time_t limit);
 extern void key_schedule_gc(time_t expiry_at);
+extern void key_gc_keytype(struct key_type *ktype);
 
 extern int key_task_permission(const key_ref_t key_ref,
 			       const struct cred *cred,
diff --git a/security/keys/key.c b/security/keys/key.c
index f7f9d93f08d9..4414abddcb5b 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -21,7 +21,7 @@
 #include <linux/user_namespace.h>
 #include "internal.h"
 
-static struct kmem_cache	*key_jar;
+struct kmem_cache *key_jar;
 struct rb_root		key_serial_tree; /* tree of keys indexed by serial */
 DEFINE_SPINLOCK(key_serial_lock);
 
@@ -36,17 +36,9 @@ unsigned int key_quota_maxbytes = 20000;	/* general key space quota */
 static LIST_HEAD(key_types_list);
 static DECLARE_RWSEM(key_types_sem);
 
-static void key_cleanup(struct work_struct *work);
-static DECLARE_WORK(key_cleanup_task, key_cleanup);
-
 /* We serialise key instantiation and link */
 DEFINE_MUTEX(key_construction_mutex);
 
-/* Any key who's type gets unegistered will be re-typed to this */
-static struct key_type key_type_dead = {
-	.name		= "dead",
-};
-
 #ifdef KEY_DEBUGGING
 void __key_check(const struct key *key)
 {
@@ -591,71 +583,6 @@ int key_reject_and_link(struct key *key,
 }
 EXPORT_SYMBOL(key_reject_and_link);
 
-/*
- * Garbage collect keys in process context so that we don't have to disable
- * interrupts all over the place.
- *
- * key_put() schedules this rather than trying to do the cleanup itself, which
- * means key_put() doesn't have to sleep.
- */
-static void key_cleanup(struct work_struct *work)
-{
-	struct rb_node *_n;
-	struct key *key;
-
-go_again:
-	/* look for a dead key in the tree */
-	spin_lock(&key_serial_lock);
-
-	for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) {
-		key = rb_entry(_n, struct key, serial_node);
-
-		if (atomic_read(&key->usage) == 0)
-			goto found_dead_key;
-	}
-
-	spin_unlock(&key_serial_lock);
-	return;
-
-found_dead_key:
-	/* we found a dead key - once we've removed it from the tree, we can
-	 * drop the lock */
-	rb_erase(&key->serial_node, &key_serial_tree);
-	spin_unlock(&key_serial_lock);
-
-	key_check(key);
-
-	security_key_free(key);
-
-	/* deal with the user's key tracking and quota */
-	if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
-		spin_lock(&key->user->lock);
-		key->user->qnkeys--;
-		key->user->qnbytes -= key->quotalen;
-		spin_unlock(&key->user->lock);
-	}
-
-	atomic_dec(&key->user->nkeys);
-	if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
-		atomic_dec(&key->user->nikeys);
-
-	key_user_put(key->user);
-
-	/* now throw away the key memory */
-	if (key->type->destroy)
-		key->type->destroy(key);
-
-	kfree(key->description);
-
-#ifdef KEY_DEBUGGING
-	key->magic = KEY_DEBUG_MAGIC_X;
-#endif
-	kmem_cache_free(key_jar, key);
-
-	/* there may, of course, be more than one key to destroy */
-	goto go_again;
-}
-
 /**
  * key_put - Discard a reference to a key.
  * @key: The key to discard a reference from.
@@ -670,7 +597,7 @@ void key_put(struct key *key)
 		key_check(key);
 
 		if (atomic_dec_and_test(&key->usage))
-			schedule_work(&key_cleanup_task);
+			queue_work(system_nrt_wq, &key_gc_work);
 	}
 }
 EXPORT_SYMBOL(key_put);
@@ -1048,49 +975,11 @@ EXPORT_SYMBOL(register_key_type);
  */
 void unregister_key_type(struct key_type *ktype)
 {
-	struct rb_node *_n;
-	struct key *key;
-
 	down_write(&key_types_sem);
-
-	/* withdraw the key type */
 	list_del_init(&ktype->link);
-
-	/* mark all the keys of this type dead */
-	spin_lock(&key_serial_lock);
-
-	for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) {
-		key = rb_entry(_n, struct key, serial_node);
-
-		if (key->type == ktype) {
-			key->type = &key_type_dead;
-			set_bit(KEY_FLAG_DEAD, &key->flags);
-		}
-	}
-
-	spin_unlock(&key_serial_lock);
-
-	/* make sure everyone revalidates their keys */
-	synchronize_rcu();
-
-	/* we should now be able to destroy the payloads of all the keys of
-	 * this type with impunity */
-	spin_lock(&key_serial_lock);
-
-	for (_n = rb_first(&key_serial_tree); _n; _n = rb_next(_n)) {
-		key = rb_entry(_n, struct key, serial_node);
-
-		if (key->type == ktype) {
-			if (ktype->destroy)
-				ktype->destroy(key);
-			memset(&key->payload, KEY_DESTROY, sizeof(key->payload));
-		}
-	}
-
-	spin_unlock(&key_serial_lock);
-	up_write(&key_types_sem);
-
-	key_schedule_gc(0);
+	downgrade_write(&key_types_sem);
+	key_gc_keytype(ktype);
+	up_read(&key_types_sem);
 }
 EXPORT_SYMBOL(unregister_key_type);
 
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 30e242f7bd0e..37a7f3b28852 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -860,8 +860,7 @@ void __key_link(struct key *keyring, struct key *key,
 
 	kenter("%d,%d,%p", keyring->serial, key->serial, nklist);
 
-	klist = rcu_dereference_protected(keyring->payload.subscriptions,
-					  rwsem_is_locked(&keyring->sem));
+	klist = rcu_dereference_locked_keyring(keyring);
 
 	atomic_inc(&key->usage);
 
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index a3063eb3dc23..1068cb1939b3 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -270,7 +270,7 @@ static int install_session_keyring(struct key *keyring)
 	if (!new)
 		return -ENOMEM;
 
-	ret = install_session_keyring_to_cred(new, NULL);
+	ret = install_session_keyring_to_cred(new, keyring);
 	if (ret < 0) {
 		abort_creds(new);
 		return ret;
@@ -589,12 +589,22 @@ try_again:
 			ret = install_user_keyrings();
 			if (ret < 0)
 				goto error;
-			ret = install_session_keyring(
-				cred->user->session_keyring);
+			if (lflags & KEY_LOOKUP_CREATE)
+				ret = join_session_keyring(NULL);
+			else
+				ret = install_session_keyring(
+					cred->user->session_keyring);
 
 			if (ret < 0)
 				goto error;
 			goto reget_creds;
+		} else if (cred->tgcred->session_keyring ==
+			   cred->user->session_keyring &&
+			   lflags & KEY_LOOKUP_CREATE) {
+			ret = join_session_keyring(NULL);
+			if (ret < 0)
+				goto error;
+			goto reget_creds;
 		}
 
 		rcu_read_lock();
diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index 0c33e2ea1f3c..0964fc236946 100644
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -779,7 +779,10 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
 			opt->pcrinfo_len = strlen(args[0].from) / 2;
 			if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
 				return -EINVAL;
-			hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len);
+			res = hex2bin(opt->pcrinfo, args[0].from,
+				      opt->pcrinfo_len);
+			if (res < 0)
+				return -EINVAL;
 			break;
 		case Opt_keyhandle:
 			res = strict_strtoul(args[0].from, 16, &handle);
@@ -791,12 +794,18 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
 		case Opt_keyauth:
 			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 				return -EINVAL;
-			hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE);
+			res = hex2bin(opt->keyauth, args[0].from,
+				      SHA1_DIGEST_SIZE);
+			if (res < 0)
+				return -EINVAL;
 			break;
 		case Opt_blobauth:
 			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 				return -EINVAL;
-			hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE);
+			res = hex2bin(opt->blobauth, args[0].from,
+				      SHA1_DIGEST_SIZE);
+			if (res < 0)
+				return -EINVAL;
 			break;
 		case Opt_migratable:
 			if (*args[0].from == '0')
@@ -860,7 +869,9 @@ static int datablob_parse(char *datablob, struct trusted_key_payload *p,
 		p->blob_len = strlen(c) / 2;
 		if (p->blob_len > MAX_BLOB_SIZE)
 			return -EINVAL;
-		hex2bin(p->blob, c, p->blob_len);
+		ret = hex2bin(p->blob, c, p->blob_len);
+		if (ret < 0)
+			return -EINVAL;
 		ret = getoptions(datablob, p, o);
 		if (ret < 0)
 			return ret;