Merge /spare/repo/linux-2.6/

11 files changed, 990 insertions, 418 deletions

diff --git a/security/keys/Makefile b/security/keys/Makefile
index ddb495d65062..c392d750b208 100644
--- a/security/keys/Makefile
+++ b/security/keys/Makefile
@@ -7,8 +7,9 @@ obj-y := \
 	keyring.o \
 	keyctl.o \
 	process_keys.o \
-	user_defined.o \
-	request_key.o
+	request_key.o \
+	request_key_auth.o \
+	user_defined.o
 
 obj-$(CONFIG_KEYS_COMPAT) += compat.o
 obj-$(CONFIG_PROC_FS) += proc.o
diff --git a/security/keys/compat.c b/security/keys/compat.c
index aff8b22dcb5c..3303673c636e 100644
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -1,6 +1,6 @@
 /* compat.c: 32-bit compatibility syscall for 64-bit systems
  *
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -24,7 +24,7 @@
  * - if you can, you should call sys_keyctl directly
  */
 asmlinkage long compat_sys_keyctl(u32 option,
-			      u32 arg2, u32 arg3, u32 arg4, u32 arg5)
+				  u32 arg2, u32 arg3, u32 arg4, u32 arg5)
 {
 	switch (option) {
 	case KEYCTL_GET_KEYRING_ID:
@@ -71,6 +71,9 @@ asmlinkage long compat_sys_keyctl(u32 option,
 	case KEYCTL_NEGATE:
 		return keyctl_negate_key(arg2, arg3, arg4);
 
+	case KEYCTL_SET_REQKEY_KEYRING:
+		return keyctl_set_reqkey_keyring(arg2);
+
 	default:
 		return -EOPNOTSUPP;
 	}
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 67b2b93a7489..46c8602661c9 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -1,6 +1,6 @@
 /* internal.h: authentication token and access key management internal defs
  *
- * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -15,6 +15,16 @@
 #include <linux/key.h>
 #include <linux/key-ui.h>
 
+#if 0
+#define kenter(FMT, a...)	printk("==> %s("FMT")\n",__FUNCTION__ , ## a)
+#define kleave(FMT, a...)	printk("<== %s()"FMT"\n",__FUNCTION__ , ## a)
+#define kdebug(FMT, a...)	printk(FMT"\n" , ## a)
+#else
+#define kenter(FMT, a...)	do {} while(0)
+#define kleave(FMT, a...)	do {} while(0)
+#define kdebug(FMT, a...)	do {} while(0)
+#endif
+
 extern struct key_type key_type_dead;
 extern struct key_type key_type_user;
 
@@ -66,20 +76,46 @@ extern struct key *__keyring_search_one(struct key *keyring,
 					const char *description,
 					key_perm_t perm);
 
+extern struct key *keyring_search_instkey(struct key *keyring,
+					  key_serial_t target_id);
+
 typedef int (*key_match_func_t)(const struct key *, const void *);
 
 extern struct key *keyring_search_aux(struct key *keyring,
+				      struct task_struct *tsk,
 				      struct key_type *type,
 				      const void *description,
 				      key_match_func_t match);
 
-extern struct key *search_process_keyrings_aux(struct key_type *type,
-					       const void *description,
-					       key_match_func_t match);
+extern struct key *search_process_keyrings(struct key_type *type,
+					   const void *description,
+					   key_match_func_t match,
+					   struct task_struct *tsk);
 
 extern struct key *find_keyring_by_name(const char *name, key_serial_t bound);
 
 extern int install_thread_keyring(struct task_struct *tsk);
+extern int install_process_keyring(struct task_struct *tsk);
+
+extern struct key *request_key_and_link(struct key_type *type,
+					const char *description,
+					const char *callout_info,
+					struct key *dest_keyring);
+
+/*
+ * request_key authorisation
+ */
+struct request_key_auth {
+	struct key		*target_key;
+	struct task_struct	*context;
+	pid_t			pid;
+};
+
+extern struct key_type key_type_request_key_auth;
+extern struct key *request_key_auth_new(struct key *target,
+					struct key **_rkakey);
+
+extern struct key *key_get_instantiation_authkey(key_serial_t target_id);
 
 /*
  * keyctl functions
@@ -100,6 +136,7 @@ extern long keyctl_setperm_key(key_serial_t, key_perm_t);
 extern long keyctl_instantiate_key(key_serial_t, const void __user *,
 				   size_t, key_serial_t);
 extern long keyctl_negate_key(key_serial_t, unsigned, key_serial_t);
+extern long keyctl_set_reqkey_keyring(int);
 
 
 /*
diff --git a/security/keys/key.c b/security/keys/key.c
index 59402c843203..fb89f9844465 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -1,6 +1,6 @@
 /* key.c: basic authentication token and access key management
  *
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -294,7 +294,6 @@ struct key *key_alloc(struct key_type *type, const char *desc,
 	}
 
 	atomic_set(&key->usage, 1);
-	rwlock_init(&key->lock);
 	init_rwsem(&key->sem);
 	key->type = type;
 	key->user = user;
@@ -308,7 +307,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
 	key->payload.data = NULL;
 
 	if (!not_in_quota)
-		key->flags |= KEY_FLAG_IN_QUOTA;
+		key->flags |= 1 << KEY_FLAG_IN_QUOTA;
 
 	memset(&key->type_data, 0, sizeof(key->type_data));
 
@@ -359,7 +358,7 @@ int key_payload_reserve(struct key *key, size_t datalen)
 	key_check(key);
 
 	/* contemplate the quota adjustment */
-	if (delta != 0 && key->flags & KEY_FLAG_IN_QUOTA) {
+	if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
 		spin_lock(&key->user->lock);
 
 		if (delta > 0 &&
@@ -392,7 +391,8 @@ EXPORT_SYMBOL(key_payload_reserve);
 static int __key_instantiate_and_link(struct key *key,
 				      const void *data,
 				      size_t datalen,
-				      struct key *keyring)
+				      struct key *keyring,
+				      struct key *instkey)
 {
 	int ret, awaken;
 
@@ -405,27 +405,25 @@ static int __key_instantiate_and_link(struct key *key,
 	down_write(&key_construction_sem);
 
 	/* can't instantiate twice */
-	if (!(key->flags & KEY_FLAG_INSTANTIATED)) {
+	if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
 		/* instantiate the key */
 		ret = key->type->instantiate(key, data, datalen);
 
 		if (ret == 0) {
 			/* mark the key as being instantiated */
-			write_lock(&key->lock);
-
 			atomic_inc(&key->user->nikeys);
-			key->flags |= KEY_FLAG_INSTANTIATED;
+			set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
 
-			if (key->flags & KEY_FLAG_USER_CONSTRUCT) {
-				key->flags &= ~KEY_FLAG_USER_CONSTRUCT;
+			if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))
 				awaken = 1;
-			}
-
-			write_unlock(&key->lock);
 
 			/* and link it into the destination keyring */
 			if (keyring)
 				ret = __key_link(keyring, key);
+
+			/* disable the authorisation key */
+			if (instkey)
+				key_revoke(instkey);
 		}
 	}
 
@@ -446,19 +444,21 @@ static int __key_instantiate_and_link(struct key *key,
 int key_instantiate_and_link(struct key *key,
 			     const void *data,
 			     size_t datalen,
-			     struct key *keyring)
+			     struct key *keyring,
+			     struct key *instkey)
 {
 	int ret;
 
 	if (keyring)
 		down_write(&keyring->sem);
 
-	ret = __key_instantiate_and_link(key, data, datalen, keyring);
+	ret = __key_instantiate_and_link(key, data, datalen, keyring, instkey);
 
 	if (keyring)
 		up_write(&keyring->sem);
 
 	return ret;
+
 } /* end key_instantiate_and_link() */
 
 EXPORT_SYMBOL(key_instantiate_and_link);
@@ -469,7 +469,8 @@ EXPORT_SYMBOL(key_instantiate_and_link);
  */
 int key_negate_and_link(struct key *key,
 			unsigned timeout,
-			struct key *keyring)
+			struct key *keyring,
+			struct key *instkey)
 {
 	struct timespec now;
 	int ret, awaken;
@@ -486,26 +487,26 @@ int key_negate_and_link(struct key *key,
 	down_write(&key_construction_sem);
 
 	/* can't instantiate twice */
-	if (!(key->flags & KEY_FLAG_INSTANTIATED)) {
+	if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
 		/* mark the key as being negatively instantiated */
-		write_lock(&key->lock);
-
 		atomic_inc(&key->user->nikeys);
-		key->flags |= KEY_FLAG_INSTANTIATED | KEY_FLAG_NEGATIVE;
+		set_bit(KEY_FLAG_NEGATIVE, &key->flags);
+		set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
 		now = current_kernel_time();
 		key->expiry = now.tv_sec + timeout;
 
-		if (key->flags & KEY_FLAG_USER_CONSTRUCT) {
-			key->flags &= ~KEY_FLAG_USER_CONSTRUCT;
+		if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))
 			awaken = 1;
-		}
 
-		write_unlock(&key->lock);
 		ret = 0;
 
 		/* and link it into the destination keyring */
 		if (keyring)
 			ret = __key_link(keyring, key);
+
+		/* disable the authorisation key */
+		if (instkey)
+			key_revoke(instkey);
 	}
 
 	up_write(&key_construction_sem);
@@ -553,8 +554,10 @@ static void key_cleanup(void *data)
 	rb_erase(&key->serial_node, &key_serial_tree);
 	spin_unlock(&key_serial_lock);
 
+	key_check(key);
+
 	/* deal with the user's key tracking and quota */
-	if (key->flags & KEY_FLAG_IN_QUOTA) {
+	if (test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
 		spin_lock(&key->user->lock);
 		key->user->qnkeys--;
 		key->user->qnbytes -= key->quotalen;
@@ -562,7 +565,7 @@ static void key_cleanup(void *data)
 	}
 
 	atomic_dec(&key->user->nkeys);
-	if (key->flags & KEY_FLAG_INSTANTIATED)
+	if (test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
 		atomic_dec(&key->user->nikeys);
 
 	key_user_put(key->user);
@@ -631,9 +634,9 @@ struct key *key_lookup(key_serial_t id)
 	goto error;
 
  found:
-	/* pretent doesn't exist if it's dead */
+	/* pretend it doesn't exist if it's dead */
 	if (atomic_read(&key->usage) == 0 ||
-	    (key->flags & KEY_FLAG_DEAD) ||
+	    test_bit(KEY_FLAG_DEAD, &key->flags) ||
 	    key->type == &key_type_dead)
 		goto not_found;
 
@@ -708,12 +711,9 @@ static inline struct key *__key_update(struct key *key, const void *payload,
 
 	ret = key->type->update(key, payload, plen);
 
-	if (ret == 0) {
+	if (ret == 0)
 		/* updating a negative key instantiates it */
-		write_lock(&key->lock);
-		key->flags &= ~KEY_FLAG_NEGATIVE;
-		write_unlock(&key->lock);
-	}
+		clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
 
 	up_write(&key->sem);
 
@@ -793,7 +793,7 @@ struct key *key_create_or_update(struct key *keyring,
 	}
 
 	/* instantiate it and link it into the target keyring */
-	ret = __key_instantiate_and_link(key, payload, plen, keyring);
+	ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL);
 	if (ret < 0) {
 		key_put(key);
 		key = ERR_PTR(ret);
@@ -841,12 +841,9 @@ int key_update(struct key *key, const void *payload, size_t plen)
 		down_write(&key->sem);
 		ret = key->type->update(key, payload, plen);
 
-		if (ret == 0) {
+		if (ret == 0)
 			/* updating a negative key instantiates it */
-			write_lock(&key->lock);
-			key->flags &= ~KEY_FLAG_NEGATIVE;
-			write_unlock(&key->lock);
-		}
+			clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
 
 		up_write(&key->sem);
 	}
@@ -892,10 +889,7 @@ struct key *key_duplicate(struct key *source, const char *desc)
 		goto error2;
 
 	atomic_inc(&key->user->nikeys);
-
-	write_lock(&key->lock);
-	key->flags |= KEY_FLAG_INSTANTIATED;
-	write_unlock(&key->lock);
+	set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
 
  error_k:
 	up_read(&key_types_sem);
@@ -922,9 +916,7 @@ void key_revoke(struct key *key)
 	/* make sure no one's trying to change or use the key when we mark
 	 * it */
 	down_write(&key->sem);
-	write_lock(&key->lock);
-	key->flags |= KEY_FLAG_REVOKED;
-	write_unlock(&key->lock);
+	set_bit(KEY_FLAG_REVOKED, &key->flags);
 	up_write(&key->sem);
 
 } /* end key_revoke() */
@@ -975,24 +967,33 @@ void unregister_key_type(struct key_type *ktype)
 	/* withdraw the key type */
 	list_del_init(&ktype->link);
 
-	/* need to withdraw all keys of this type */
+	/* 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)
-			continue;
+		if (key->type == ktype)
+			key->type = &key_type_dead;
+	}
+
+	spin_unlock(&key_serial_lock);
+
+	/* make sure everyone revalidates their keys */
+	synchronize_rcu();
 
-		write_lock(&key->lock);
-		key->type = &key_type_dead;
-		write_unlock(&key->lock);
+	/* 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);
 
-		/* there shouldn't be anyone looking at the description or
-		 * payload now */
-		if (ktype->destroy)
-			ktype->destroy(key);
-		memset(&key->payload, 0xbd, sizeof(key->payload));
+		if (key->type == ktype) {
+			if (ktype->destroy)
+				ktype->destroy(key);
+			memset(&key->payload, 0xbd, sizeof(key->payload));
+		}
 	}
 
 	spin_unlock(&key_serial_lock);
@@ -1037,4 +1038,5 @@ void __init key_init(void)
 
 	/* link the two root keyrings together */
 	key_link(&root_session_keyring, &root_user_keyring);
+
 } /* end key_init() */
diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index dc0011b3fac9..fea262860ea0 100644
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1,6 +1,6 @@
 /* keyctl.c: userspace keyctl operations
  *
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -49,6 +49,13 @@ asmlinkage long sys_add_key(const char __user *_type,
 		goto error;
 	type[31] = '\0';
 
+	if (!type[0])
+		goto error;
+
+	ret = -EPERM;
+	if (type[0] == '.')
+		goto error;
+
 	ret = -EFAULT;
 	dlen = strnlen_user(_description, PAGE_SIZE - 1);
 	if (dlen <= 0)
@@ -82,7 +89,7 @@ asmlinkage long sys_add_key(const char __user *_type,
 	}
 
 	/* find the target keyring (which must be writable) */
-	keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+	keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);
 		goto error3;
@@ -181,7 +188,7 @@ asmlinkage long sys_request_key(const char __user *_type,
 	/* get the destination keyring if specified */
 	dest = NULL;
 	if (destringid) {
-		dest = lookup_user_key(destringid, 1, 0, KEY_WRITE);
+		dest = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE);
 		if (IS_ERR(dest)) {
 			ret = PTR_ERR(dest);
 			goto error3;
@@ -196,23 +203,15 @@ asmlinkage long sys_request_key(const char __user *_type,
 	}
 
 	/* do the search */
-	key = request_key(ktype, description, callout_info);
+	key = request_key_and_link(ktype, description, callout_info, dest);
 	if (IS_ERR(key)) {
 		ret = PTR_ERR(key);
 		goto error5;
 	}
 
-	/* link the resulting key to the destination keyring */
-	if (dest) {
-		ret = key_link(dest, key);
-		if (ret < 0)
-			goto error6;
-	}
-
 	ret = key->serial;
 
- error6:
-	key_put(key);
+ 	key_put(key);
  error5:
 	key_type_put(ktype);
  error4:
@@ -237,7 +236,7 @@ long keyctl_get_keyring_ID(key_serial_t id, int create)
 	struct key *key;
 	long ret;
 
-	key = lookup_user_key(id, create, 0, KEY_SEARCH);
+	key = lookup_user_key(NULL, id, create, 0, KEY_SEARCH);
 	if (IS_ERR(key)) {
 		ret = PTR_ERR(key);
 		goto error;
@@ -324,7 +323,7 @@ long keyctl_update_key(key_serial_t id,
 	}
 
 	/* find the target key (which must be writable) */
-	key = lookup_user_key(id, 0, 0, KEY_WRITE);
+	key = lookup_user_key(NULL, id, 0, 0, KEY_WRITE);
 	if (IS_ERR(key)) {
 		ret = PTR_ERR(key);
 		goto error2;
@@ -352,7 +351,7 @@ long keyctl_revoke_key(key_serial_t id)
 	struct key *key;
 	long ret;
 
-	key = lookup_user_key(id, 0, 0, KEY_WRITE);
+	key = lookup_user_key(NULL, id, 0, 0, KEY_WRITE);
 	if (IS_ERR(key)) {
 		ret = PTR_ERR(key);
 		goto error;
@@ -378,7 +377,7 @@ long keyctl_keyring_clear(key_serial_t ringid)
 	struct key *keyring;
 	long ret;
 
-	keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+	keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);
 		goto error;
@@ -404,13 +403,13 @@ long keyctl_keyring_link(key_serial_t id, key_serial_t ringid)
 	struct key *keyring, *key;
 	long ret;
 
-	keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+	keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);
 		goto error;
 	}
 
-	key = lookup_user_key(id, 1, 0, KEY_LINK);
+	key = lookup_user_key(NULL, id, 1, 0, KEY_LINK);
 	if (IS_ERR(key)) {
 		ret = PTR_ERR(key);
 		goto error2;
@@ -438,13 +437,13 @@ long keyctl_keyring_unlink(key_serial_t id, key_serial_t ringid)
 	struct key *keyring, *key;
 	long ret;
 
-	keyring = lookup_user_key(ringid, 0, 0, KEY_WRITE);
+	keyring = lookup_user_key(NULL, ringid, 0, 0, KEY_WRITE);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);
 		goto error;
 	}
 
-	key = lookup_user_key(id, 0, 0, 0);
+	key = lookup_user_key(NULL, id, 0, 0, 0);
 	if (IS_ERR(key)) {
 		ret = PTR_ERR(key);
 		goto error2;
@@ -475,16 +474,29 @@ long keyctl_describe_key(key_serial_t keyid,
 			 char __user *buffer,
 			 size_t buflen)
 {
-	struct key *key;
+	struct key *key, *instkey;
 	char *tmpbuf;
 	long ret;
 
-	key = lookup_user_key(keyid, 0, 1, KEY_VIEW);
+	key = lookup_user_key(NULL, keyid, 0, 1, KEY_VIEW);
 	if (IS_ERR(key)) {
+		/* viewing a key under construction is permitted if we have the
+		 * authorisation token handy */
+		if (PTR_ERR(key) == -EACCES) {
+			instkey = key_get_instantiation_authkey(keyid);
+			if (!IS_ERR(instkey)) {
+				key_put(instkey);
+				key = lookup_user_key(NULL, keyid, 0, 1, 0);
+				if (!IS_ERR(key))
+					goto okay;
+			}
+		}
+
 		ret = PTR_ERR(key);
 		goto error;
 	}
 
+okay:
 	/* calculate how much description we're going to return */
 	ret = -ENOMEM;
 	tmpbuf = kmalloc(PAGE_SIZE, GFP_KERNEL);
@@ -568,7 +580,7 @@ long keyctl_keyring_search(key_serial_t ringid,
 		goto error2;
 
 	/* get the keyring at which to begin the search */
-	keyring = lookup_user_key(ringid, 0, 0, KEY_SEARCH);
+	keyring = lookup_user_key(NULL, ringid, 0, 0, KEY_SEARCH);
 	if (IS_ERR(keyring)) {
 		ret = PTR_ERR(keyring);
 		goto error2;
@@ -577,7 +589,7 @@ long keyctl_keyring_search(key_serial_t ringid,
 	/* get the destination keyring if specified */
 	dest = NULL;
 	if (destringid) {
-		dest = lookup_user_key(destringid, 1, 0, KEY_WRITE);
+		dest = lookup_user_key(NULL, destringid, 1, 0, KEY_WRITE);
 		if (IS_ERR(dest)) {
 			ret = PTR_ERR(dest);
 			goto error3;
@@ -656,24 +668,23 @@ long keyctl_read_key(key_serial_t keyid, char __user *buffer, size_t buflen)
 	long ret;
 
 	/* find the key first */
-	key = lookup_user_key(keyid, 0, 0, 0);
+	key = lookup_user_key(NULL, keyid, 0, 0, 0);
 	if (!IS_ERR(key)) {
 		/* see if we can read it directly */
 		if (key_permission(key, KEY_READ))
 			goto can_read_key;
 
-		/* can't; see if it's searchable from this process's
-		 * keyrings */
-		ret = -ENOKEY;
-		if (key_permission(key, KEY_SEARCH)) {
-			/* okay - we do have search permission on the key
-			 * itself, but do we have the key? */
-			skey = search_process_keyrings_aux(key->type, key,
-							   keyctl_read_key_same);
-			if (!IS_ERR(skey))
-				goto can_read_key2;
-		}
-
+		/* we can't; see if it's searchable from this process's
+		 * keyrings
+		 * - we automatically take account of the fact that it may be
+		 *   dangling off an instantiation key
+		 */
+		skey = search_process_keyrings(key->type, key,
+					       keyctl_read_key_same, current);
+		if (!IS_ERR(skey))
+			goto can_read_key2;
+
+		ret = PTR_ERR(skey);
 		goto error2;
 	}
 
@@ -719,7 +730,7 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
 	if (uid == (uid_t) -1 && gid == (gid_t) -1)
 		goto error;
 
-	key = lookup_user_key(id, 1, 1, 0);
+	key = lookup_user_key(NULL, id, 1, 1, 0);
 	if (IS_ERR(key)) {
 		ret = PTR_ERR(key);
 		goto error;
@@ -728,7 +739,6 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
 	/* make the changes with the locks held to prevent chown/chown races */
 	ret = -EACCES;
 	down_write(&key->sem);
-	write_lock(&key->lock);
 
 	if (!capable(CAP_SYS_ADMIN)) {
 		/* only the sysadmin can chown a key to some other UID */
@@ -755,7 +765,6 @@ long keyctl_chown_key(key_serial_t id, uid_t uid, gid_t gid)
 	ret = 0;
 
  no_access:
-	write_unlock(&key->lock);
 	up_write(&key->sem);
 	key_put(key);
  error:
@@ -778,32 +787,25 @@ long keyctl_setperm_key(key_serial_t id, key_perm_t perm)
 	if (perm & ~(KEY_USR_ALL | KEY_GRP_ALL | KEY_OTH_ALL))
 		goto error;
 
-	key = lookup_user_key(id, 1, 1, 0);
+	key = lookup_user_key(NULL, id, 1, 1, 0);
 	if (IS_ERR(key)) {
 		ret = PTR_ERR(key);
 		goto error;
 	}
 
-	/* make the changes with the locks held to prevent chown/chmod
-	 * races */
+	/* make the changes with the locks held to prevent chown/chmod races */
 	ret = -EACCES;
 	down_write(&key->sem);
-	write_lock(&key->lock);
 
-	/* if we're not the sysadmin, we can only chmod a key that we
-	 * own */
-	if (!capable(CAP_SYS_ADMIN) && key->uid != current->fsuid)
-		goto no_access;
-
-	/* changing the permissions mask */
-	key->perm = perm;
-	ret = 0;
+	/* if we're not the sysadmin, we can only change a key that we own */
+	if (capable(CAP_SYS_ADMIN) || key->uid == current->fsuid) {
+		key->perm = perm;
+		ret = 0;
+	}
 
- no_access:
-	write_unlock(&key->lock);
 	up_write(&key->sem);
 	key_put(key);
- error:
+error:
 	return ret;
 
 } /* end keyctl_setperm_key() */
@@ -818,7 +820,8 @@ long keyctl_instantiate_key(key_serial_t id,
 			    size_t plen,
 			    key_serial_t ringid)
 {
-	struct key *key, *keyring;
+	struct request_key_auth *rka;
+	struct key *instkey, *keyring;
 	void *payload;
 	long ret;
 
@@ -840,18 +843,21 @@ long keyctl_instantiate_key(key_serial_t id,
 			goto error2;
 	}
 
-	/* find the target key (which must be writable) */
-	key = lookup_user_key(id, 0, 1, KEY_WRITE);
-	if (IS_ERR(key)) {
-		ret = PTR_ERR(key);
+	/* find the instantiation authorisation key */
+	instkey = key_get_instantiation_authkey(id);
+	if (IS_ERR(instkey)) {
+		ret = PTR_ERR(instkey);
 		goto error2;
 	}
 
-	/* find the destination keyring if present (which must also be
-	 * writable) */
+	rka = instkey->payload.data;
+
+	/* find the destination keyring amongst those belonging to the
+	 * requesting task */
 	keyring = NULL;
 	if (ringid) {
-		keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+		keyring = lookup_user_key(rka->context, ringid, 1, 0,
+					  KEY_WRITE);
 		if (IS_ERR(keyring)) {
 			ret = PTR_ERR(keyring);
 			goto error3;
@@ -859,11 +865,12 @@ long keyctl_instantiate_key(key_serial_t id,
 	}
 
 	/* instantiate the key and link it into a keyring */
-	ret = key_instantiate_and_link(key, payload, plen, keyring);
+	ret = key_instantiate_and_link(rka->target_key, payload, plen,
+				       keyring, instkey);
 
 	key_put(keyring);
  error3:
-	key_put(key);
+	key_put(instkey);
  error2:
 	kfree(payload);
  error:
@@ -878,21 +885,24 @@ long keyctl_instantiate_key(key_serial_t id,
  */
 long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
 {
-	struct key *key, *keyring;
+	struct request_key_auth *rka;
+	struct key *instkey, *keyring;
 	long ret;
 
-	/* find the target key (which must be writable) */
-	key = lookup_user_key(id, 0, 1, KEY_WRITE);
-	if (IS_ERR(key)) {
-		ret = PTR_ERR(key);
+	/* find the instantiation authorisation key */
+	instkey = key_get_instantiation_authkey(id);
+	if (IS_ERR(instkey)) {
+		ret = PTR_ERR(instkey);
 		goto error;
 	}
 
+	rka = instkey->payload.data;
+
 	/* find the destination keyring if present (which must also be
 	 * writable) */
 	keyring = NULL;
 	if (ringid) {
-		keyring = lookup_user_key(ringid, 1, 0, KEY_WRITE);
+		keyring = lookup_user_key(NULL, ringid, 1, 0, KEY_WRITE);
 		if (IS_ERR(keyring)) {
 			ret = PTR_ERR(keyring);
 			goto error2;
@@ -900,11 +910,11 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
 	}
 
 	/* instantiate the key and link it into a keyring */
-	ret = key_negate_and_link(key, timeout, keyring);
+	ret = key_negate_and_link(rka->target_key, timeout, keyring, instkey);
 
 	key_put(keyring);
  error2:
-	key_put(key);
+	key_put(instkey);
  error:
 	return ret;
 
@@ -912,6 +922,44 @@ long keyctl_negate_key(key_serial_t id, unsigned timeout, key_serial_t ringid)
 
 /*****************************************************************************/
 /*
+ * set the default keyring in which request_key() will cache keys
+ * - return the old setting
+ */
+long keyctl_set_reqkey_keyring(int reqkey_defl)
+{
+	int ret;
+
+	switch (reqkey_defl) {
+	case KEY_REQKEY_DEFL_THREAD_KEYRING:
+		ret = install_thread_keyring(current);
+		if (ret < 0)
+			return ret;
+		goto set;
+
+	case KEY_REQKEY_DEFL_PROCESS_KEYRING:
+		ret = install_process_keyring(current);
+		if (ret < 0)
+			return ret;
+
+	case KEY_REQKEY_DEFL_DEFAULT:
+	case KEY_REQKEY_DEFL_SESSION_KEYRING:
+	case KEY_REQKEY_DEFL_USER_KEYRING:
+	case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
+	set:
+		current->jit_keyring = reqkey_defl;
+
+	case KEY_REQKEY_DEFL_NO_CHANGE:
+		return current->jit_keyring;
+
+	case KEY_REQKEY_DEFL_GROUP_KEYRING:
+	default:
+		return -EINVAL;
+	}
+
+} /* end keyctl_set_reqkey_keyring() */
+
+/*****************************************************************************/
+/*
  * the key control system call
  */
 asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3,
@@ -980,6 +1028,9 @@ asmlinkage long sys_keyctl(int option, unsigned long arg2, unsigned long arg3,
 					 (unsigned) arg3,
 					 (key_serial_t) arg4);
 
+	case KEYCTL_SET_REQKEY_KEYRING:
+		return keyctl_set_reqkey_keyring(arg2);
+
 	default:
 		return -EOPNOTSUPP;
 	}
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index e2ab4f8e7481..90a551e4da66 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -1,6 +1,6 @@
 /* keyring.c: keyring handling
  *
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -132,10 +132,17 @@ static int keyring_duplicate(struct key *keyring, const struct key *source)
 		(PAGE_SIZE - sizeof(*klist)) / sizeof(struct key);
 
 	ret = 0;
-	sklist = source->payload.subscriptions;
 
-	if (sklist && sklist->nkeys > 0) {
+	/* find out how many keys are currently linked */
+	rcu_read_lock();
+	sklist = rcu_dereference(source->payload.subscriptions);
+	max = 0;
+	if (sklist)
 		max = sklist->nkeys;
+	rcu_read_unlock();
+
+	/* allocate a new payload and stuff load with key links */
+	if (max > 0) {
 		BUG_ON(max > limit);
 
 		max = (max + 3) & ~3;
@@ -148,6 +155,10 @@ static int keyring_duplicate(struct key *keyring, const struct key *source)
 		if (!klist)
 			goto error;
 
+		/* set links */
+		rcu_read_lock();
+		sklist = rcu_dereference(source->payload.subscriptions);
+
 		klist->maxkeys = max;
 		klist->nkeys = sklist->nkeys;
 		memcpy(klist->keys,
@@ -157,7 +168,9 @@ static int keyring_duplicate(struct key *keyring, const struct key *source)
 		for (loop = klist->nkeys - 1; loop >= 0; loop--)
 			atomic_inc(&klist->keys[loop]->usage);
 
-		keyring->payload.subscriptions = klist;
+		rcu_read_unlock();
+
+		rcu_assign_pointer(keyring->payload.subscriptions, klist);
 		ret = 0;
 	}
 
@@ -192,7 +205,7 @@ static void keyring_destroy(struct key *keyring)
 		write_unlock(&keyring_name_lock);
 	}
 
-	klist = keyring->payload.subscriptions;
+	klist = rcu_dereference(keyring->payload.subscriptions);
 	if (klist) {
 		for (loop = klist->nkeys - 1; loop >= 0; loop--)
 			key_put(klist->keys[loop]);
@@ -216,17 +229,20 @@ static void keyring_describe(const struct key *keyring, struct seq_file *m)
 		seq_puts(m, "[anon]");
 	}
 
-	klist = keyring->payload.subscriptions;
+	rcu_read_lock();
+	klist = rcu_dereference(keyring->payload.subscriptions);
 	if (klist)
 		seq_printf(m, ": %u/%u", klist->nkeys, klist->maxkeys);
 	else
 		seq_puts(m, ": empty");
+	rcu_read_unlock();
 
 } /* end keyring_describe() */
 
 /*****************************************************************************/
 /*
  * read a list of key IDs from the keyring's contents
+ * - the keyring's semaphore is read-locked
  */
 static long keyring_read(const struct key *keyring,
 			 char __user *buffer, size_t buflen)
@@ -237,7 +253,7 @@ static long keyring_read(const struct key *keyring,
 	int loop, ret;
 
 	ret = 0;
-	klist = keyring->payload.subscriptions;
+	klist = rcu_dereference(keyring->payload.subscriptions);
 
 	if (klist) {
 		/* calculate how much data we could return */
@@ -292,7 +308,7 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
 			    uid, gid, KEY_USR_ALL, not_in_quota);
 
 	if (!IS_ERR(keyring)) {
-		ret = key_instantiate_and_link(keyring, NULL, 0, dest);
+		ret = key_instantiate_and_link(keyring, NULL, 0, dest, NULL);
 		if (ret < 0) {
 			key_put(keyring);
 			keyring = ERR_PTR(ret);
@@ -310,17 +326,18 @@ struct key *keyring_alloc(const char *description, uid_t uid, gid_t gid,
  * - we only find keys on which we have search permission
  * - we use the supplied match function to see if the description (or other
  *   feature of interest) matches
- * - we readlock the keyrings as we search down the tree
+ * - we rely on RCU to prevent the keyring lists from disappearing on us
  * - we return -EAGAIN if we didn't find any matching key
  * - we return -ENOKEY if we only found negative matching keys
  */
 struct key *keyring_search_aux(struct key *keyring,
+			       struct task_struct *context,
 			       struct key_type *type,
 			       const void *description,
 			       key_match_func_t match)
 {
 	struct {
-		struct key *keyring;
+		struct keyring_list *keylist;
 		int kix;
 	} stack[KEYRING_SEARCH_MAX_DEPTH];
 
@@ -328,13 +345,15 @@ struct key *keyring_search_aux(struct key *keyring,
 	struct timespec now;
 	struct key *key;
 	long err;
-	int sp, psp, kix;
+	int sp, kix;
 
 	key_check(keyring);
 
+	rcu_read_lock();
+
 	/* top keyring must have search permission to begin the search */
 	key = ERR_PTR(-EACCES);
-	if (!key_permission(keyring, KEY_SEARCH))
+	if (!key_task_permission(keyring, context, KEY_SEARCH))
 		goto error;
 
 	key = ERR_PTR(-ENOTDIR);
@@ -347,11 +366,10 @@ struct key *keyring_search_aux(struct key *keyring,
 
 	/* start processing a new keyring */
  descend:
-	read_lock(&keyring->lock);
-	if (keyring->flags & KEY_FLAG_REVOKED)
+	if (test_bit(KEY_FLAG_REVOKED, &keyring->flags))
 		goto not_this_keyring;
 
-	keylist = keyring->payload.subscriptions;
+	keylist = rcu_dereference(keyring->payload.subscriptions);
 	if (!keylist)
 		goto not_this_keyring;
 
@@ -364,7 +382,7 @@ struct key *keyring_search_aux(struct key *keyring,
 			continue;
 
 		/* skip revoked keys and expired keys */
-		if (key->flags & KEY_FLAG_REVOKED)
+		if (test_bit(KEY_FLAG_REVOKED, &key->flags))
 			continue;
 
 		if (key->expiry && now.tv_sec >= key->expiry)
@@ -375,11 +393,11 @@ struct key *keyring_search_aux(struct key *keyring,
 			continue;
 
 		/* key must have search permissions */
-		if (!key_permission(key, KEY_SEARCH))
+		if (!key_task_permission(key, context, KEY_SEARCH))
 			continue;
 
 		/* we set a different error code if we find a negative key */
-		if (key->flags & KEY_FLAG_NEGATIVE) {
+		if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
 			err = -ENOKEY;
 			continue;
 		}
@@ -390,48 +408,37 @@ struct key *keyring_search_aux(struct key *keyring,
 	/* search through the keyrings nested in this one */
 	kix = 0;
  ascend:
-	while (kix < keylist->nkeys) {
+	for (; kix < keylist->nkeys; kix++) {
 		key = keylist->keys[kix];
 		if (key->type != &key_type_keyring)
-			goto next;
+			continue;
 
 		/* recursively search nested keyrings
 		 * - only search keyrings for which we have search permission
 		 */
 		if (sp >= KEYRING_SEARCH_MAX_DEPTH)
-			goto next;
-
-		if (!key_permission(key, KEY_SEARCH))
-			goto next;
+			continue;
 
-		/* evade loops in the keyring tree */
-		for (psp = 0; psp < sp; psp++)
-			if (stack[psp].keyring == keyring)
-				goto next;
+		if (!key_task_permission(key, context, KEY_SEARCH))
+			continue;
 
 		/* stack the current position */
-		stack[sp].keyring = keyring;
+		stack[sp].keylist = keylist;
 		stack[sp].kix = kix;
 		sp++;
 
 		/* begin again with the new keyring */
 		keyring = key;
 		goto descend;
-
-	next:
-		kix++;
 	}
 
 	/* the keyring we're looking at was disqualified or didn't contain a
 	 * matching key */
  not_this_keyring:
-	read_unlock(&keyring->lock);
-
 	if (sp > 0) {
 		/* resume the processing of a keyring higher up in the tree */
 		sp--;
-		keyring = stack[sp].keyring;
-		keylist = keyring->payload.subscriptions;
+		keylist = stack[sp].keylist;
 		kix = stack[sp].kix + 1;
 		goto ascend;
 	}
@@ -442,16 +449,9 @@ struct key *keyring_search_aux(struct key *keyring,
 	/* we found a viable match */
  found:
 	atomic_inc(&key->usage);
-	read_unlock(&keyring->lock);
-
-	/* unwind the keyring stack */
-	while (sp > 0) {
-		sp--;
-		read_unlock(&stack[sp].keyring->lock);
-	}
-
 	key_check(key);
  error:
+	rcu_read_unlock();
 	return key;
 
 } /* end keyring_search_aux() */
@@ -469,7 +469,11 @@ struct key *keyring_search(struct key *keyring,
 			   struct key_type *type,
 			   const char *description)
 {
-	return keyring_search_aux(keyring, type, description, type->match);
+	if (!type->match)
+		return ERR_PTR(-ENOKEY);
+
+	return keyring_search_aux(keyring, current,
+				  type, description, type->match);
 
 } /* end keyring_search() */
 
@@ -489,15 +493,18 @@ struct key *__keyring_search_one(struct key *keyring,
 	struct key *key;
 	int loop;
 
-	klist = keyring->payload.subscriptions;
+	rcu_read_lock();
+
+	klist = rcu_dereference(keyring->payload.subscriptions);
 	if (klist) {
 		for (loop = 0; loop < klist->nkeys; loop++) {
 			key = klist->keys[loop];
 
 			if (key->type == ktype &&
-			    key->type->match(key, description) &&
+			    (!key->type->match ||
+			     key->type->match(key, description)) &&
 			    key_permission(key, perm) &&
-			    !(key->flags & KEY_FLAG_REVOKED)
+			    !test_bit(KEY_FLAG_REVOKED, &key->flags)
 			    )
 				goto found;
 		}
@@ -509,12 +516,58 @@ struct key *__keyring_search_one(struct key *keyring,
  found:
 	atomic_inc(&key->usage);
  error:
+	rcu_read_unlock();
 	return key;
 
 } /* end __keyring_search_one() */
 
 /*****************************************************************************/
 /*
+ * search for an instantiation authorisation key matching a target key
+ * - the RCU read lock must be held by the caller
+ * - a target_id of zero specifies any valid token
+ */
+struct key *keyring_search_instkey(struct key *keyring,
+				   key_serial_t target_id)
+{
+	struct request_key_auth *rka;
+	struct keyring_list *klist;
+	struct key *instkey;
+	int loop;
+
+	klist = rcu_dereference(keyring->payload.subscriptions);
+	if (klist) {
+		for (loop = 0; loop < klist->nkeys; loop++) {
+			instkey = klist->keys[loop];
+
+			if (instkey->type != &key_type_request_key_auth)
+				continue;
+
+			rka = instkey->payload.data;
+			if (target_id && rka->target_key->serial != target_id)
+				continue;
+
+			/* the auth key is revoked during instantiation */
+			if (!test_bit(KEY_FLAG_REVOKED, &instkey->flags))
+				goto found;
+
+			instkey = ERR_PTR(-EKEYREVOKED);
+			goto error;
+		}
+	}
+
+	instkey = ERR_PTR(-EACCES);
+	goto error;
+
+found:
+	atomic_inc(&instkey->usage);
+error:
+	return instkey;
+
+} /* end keyring_search_instkey() */
+
+/*****************************************************************************/
+/*
  * find a keyring with the specified name
  * - all named keyrings are searched
  * - only find keyrings with search permission for the process
@@ -540,7 +593,7 @@ struct key *find_keyring_by_name(const char *name, key_serial_t bound)
 				    &keyring_name_hash[bucket],
 				    type_data.link
 				    ) {
-			if (keyring->flags & KEY_FLAG_REVOKED)
+			if (test_bit(KEY_FLAG_REVOKED, &keyring->flags))
 				continue;
 
 			if (strcmp(keyring->description, name) != 0)
@@ -579,7 +632,7 @@ struct key *find_keyring_by_name(const char *name, key_serial_t bound)
 static int keyring_detect_cycle(struct key *A, struct key *B)
 {
 	struct {
-		struct key *subtree;
+		struct keyring_list *keylist;
 		int kix;
 	} stack[KEYRING_SEARCH_MAX_DEPTH];
 
@@ -587,20 +640,21 @@ static int keyring_detect_cycle(struct key *A, struct key *B)
 	struct key *subtree, *key;
 	int sp, kix, ret;
 
+	rcu_read_lock();
+
 	ret = -EDEADLK;
 	if (A == B)
-		goto error;
+		goto cycle_detected;
 
 	subtree = B;
 	sp = 0;
 
 	/* start processing a new keyring */
  descend:
-	read_lock(&subtree->lock);
-	if (subtree->flags & KEY_FLAG_REVOKED)
+	if (test_bit(KEY_FLAG_REVOKED, &subtree->flags))
 		goto not_this_keyring;
 
-	keylist = subtree->payload.subscriptions;
+	keylist = rcu_dereference(subtree->payload.subscriptions);
 	if (!keylist)
 		goto not_this_keyring;
 	kix = 0;
@@ -619,7 +673,7 @@ static int keyring_detect_cycle(struct key *A, struct key *B)
 				goto too_deep;
 
 			/* stack the current position */
-			stack[sp].subtree = subtree;
+			stack[sp].keylist = keylist;
 			stack[sp].kix = kix;
 			sp++;
 
@@ -632,13 +686,10 @@ static int keyring_detect_cycle(struct key *A, struct key *B)
 	/* the keyring we're looking at was disqualified or didn't contain a
 	 * matching key */
  not_this_keyring:
-	read_unlock(&subtree->lock);
-
 	if (sp > 0) {
 		/* resume the checking of a keyring higher up in the tree */
 		sp--;
-		subtree = stack[sp].subtree;
-		keylist = subtree->payload.subscriptions;
+		keylist = stack[sp].keylist;
 		kix = stack[sp].kix + 1;
 		goto ascend;
 	}
@@ -646,30 +697,36 @@ static int keyring_detect_cycle(struct key *A, struct key *B)
 	ret = 0; /* no cycles detected */
 
  error:
+	rcu_read_unlock();
 	return ret;
 
  too_deep:
 	ret = -ELOOP;
-	goto error_unwind;
+	goto error;
+
  cycle_detected:
 	ret = -EDEADLK;
- error_unwind:
-	read_unlock(&subtree->lock);
-
-	/* unwind the keyring stack */
-	while (sp > 0) {
-		sp--;
-		read_unlock(&stack[sp].subtree->lock);
-	}
-
 	goto error;
 
 } /* end keyring_detect_cycle() */
 
 /*****************************************************************************/
 /*
+ * dispose of a keyring list after the RCU grace period
+ */
+static void keyring_link_rcu_disposal(struct rcu_head *rcu)
+{
+	struct keyring_list *klist =
+		container_of(rcu, struct keyring_list, rcu);
+
+	kfree(klist);
+
+} /* end keyring_link_rcu_disposal() */
+
+/*****************************************************************************/
+/*
  * link a key into to a keyring
- * - must be called with the keyring's semaphore held
+ * - must be called with the keyring's semaphore write-locked
  */
 int __key_link(struct key *keyring, struct key *key)
 {
@@ -679,7 +736,7 @@ int __key_link(struct key *keyring, struct key *key)
 	int ret;
 
 	ret = -EKEYREVOKED;
-	if (keyring->flags & KEY_FLAG_REVOKED)
+	if (test_bit(KEY_FLAG_REVOKED, &keyring->flags))
 		goto error;
 
 	ret = -ENOTDIR;
@@ -710,9 +767,10 @@ int __key_link(struct key *keyring, struct key *key)
 		/* there's sufficient slack space to add directly */
 		atomic_inc(&key->usage);
 
-		write_lock(&keyring->lock);
-		klist->keys[klist->nkeys++] = key;
-		write_unlock(&keyring->lock);
+		klist->keys[klist->nkeys] = key;
+		smp_wmb();
+		klist->nkeys++;
+		smp_wmb();
 
 		ret = 0;
 	}
@@ -723,6 +781,8 @@ int __key_link(struct key *keyring, struct key *key)
 			max += klist->maxkeys;
 
 		ret = -ENFILE;
+		if (max > 65535)
+			goto error3;
 		size = sizeof(*klist) + sizeof(*key) * max;
 		if (size > PAGE_SIZE)
 			goto error3;
@@ -743,14 +803,13 @@ int __key_link(struct key *keyring, struct key *key)
 
 		/* add the key into the new space */
 		atomic_inc(&key->usage);
-
-		write_lock(&keyring->lock);
-		keyring->payload.subscriptions = nklist;
 		nklist->keys[nklist->nkeys++] = key;
-		write_unlock(&keyring->lock);
+
+		rcu_assign_pointer(keyring->payload.subscriptions, nklist);
 
 		/* dispose of the old keyring list */
-		kfree(klist);
+		if (klist)
+			call_rcu(&klist->rcu, keyring_link_rcu_disposal);
 
 		ret = 0;
 	}
@@ -791,11 +850,26 @@ EXPORT_SYMBOL(key_link);
 
 /*****************************************************************************/
 /*
+ * dispose of a keyring list after the RCU grace period, freeing the unlinked
+ * key
+ */
+static void keyring_unlink_rcu_disposal(struct rcu_head *rcu)
+{
+	struct keyring_list *klist =
+		container_of(rcu, struct keyring_list, rcu);
+
+	key_put(klist->keys[klist->delkey]);
+	kfree(klist);
+
+} /* end keyring_unlink_rcu_disposal() */
+
+/*****************************************************************************/
+/*
  * unlink the first link to a key from a keyring
  */
 int key_unlink(struct key *keyring, struct key *key)
 {
-	struct keyring_list *klist;
+	struct keyring_list *klist, *nklist;
 	int loop, ret;
 
 	key_check(keyring);
@@ -819,31 +893,45 @@ int key_unlink(struct key *keyring, struct key *key)
 	ret = -ENOENT;
 	goto error;
 
- key_is_present:
+key_is_present:
+	/* we need to copy the key list for RCU purposes */
+	nklist = kmalloc(sizeof(*klist) + sizeof(*key) * klist->maxkeys,
+			 GFP_KERNEL);
+	if (!nklist)
+		goto nomem;
+	nklist->maxkeys = klist->maxkeys;
+	nklist->nkeys = klist->nkeys - 1;
+
+	if (loop > 0)
+		memcpy(&nklist->keys[0],
+		       &klist->keys[0],
+		       loop * sizeof(klist->keys[0]));
+
+	if (loop < nklist->nkeys)
+		memcpy(&nklist->keys[loop],
+		       &klist->keys[loop + 1],
+		       (nklist->nkeys - loop) * sizeof(klist->keys[0]));
+
 	/* adjust the user's quota */
 	key_payload_reserve(keyring,
 			    keyring->datalen - KEYQUOTA_LINK_BYTES);
 
-	/* shuffle down the key pointers
-	 * - it might be worth shrinking the allocated memory, but that runs
-	 *   the risk of ENOMEM as we would have to copy
-	 */
-	write_lock(&keyring->lock);
+	rcu_assign_pointer(keyring->payload.subscriptions, nklist);
 
-	klist->nkeys--;
-	if (loop < klist->nkeys)
-		memcpy(&klist->keys[loop],
-		       &klist->keys[loop + 1],
-		       (klist->nkeys - loop) * sizeof(struct key *));
+	up_write(&keyring->sem);
 
-	write_unlock(&keyring->lock);
+	/* schedule for later cleanup */
+	klist->delkey = loop;
+	call_rcu(&klist->rcu, keyring_unlink_rcu_disposal);
 
-	up_write(&keyring->sem);
-	key_put(key);
 	ret = 0;
 
- error:
+error:
 	return ret;
+nomem:
+	ret = -ENOMEM;
+	up_write(&keyring->sem);
+	goto error;
 
 } /* end key_unlink() */
 
@@ -851,13 +939,32 @@ EXPORT_SYMBOL(key_unlink);
 
 /*****************************************************************************/
 /*
+ * dispose of a keyring list after the RCU grace period, releasing the keys it
+ * links to
+ */
+static void keyring_clear_rcu_disposal(struct rcu_head *rcu)
+{
+	struct keyring_list *klist;
+	int loop;
+
+	klist = container_of(rcu, struct keyring_list, rcu);
+
+	for (loop = klist->nkeys - 1; loop >= 0; loop--)
+		key_put(klist->keys[loop]);
+
+	kfree(klist);
+
+} /* end keyring_clear_rcu_disposal() */
+
+/*****************************************************************************/
+/*
  * clear the specified process keyring
  * - implements keyctl(KEYCTL_CLEAR)
  */
 int keyring_clear(struct key *keyring)
 {
 	struct keyring_list *klist;
-	int loop, ret;
+	int ret;
 
 	ret = -ENOTDIR;
 	if (keyring->type == &key_type_keyring) {
@@ -870,20 +977,15 @@ int keyring_clear(struct key *keyring)
 			key_payload_reserve(keyring,
 					    sizeof(struct keyring_list));
 
-			write_lock(&keyring->lock);
-			keyring->payload.subscriptions = NULL;
-			write_unlock(&keyring->lock);
+			rcu_assign_pointer(keyring->payload.subscriptions,
+					   NULL);
 		}
 
 		up_write(&keyring->sem);
 
 		/* free the keys after the locks have been dropped */
-		if (klist) {
-			for (loop = klist->nkeys - 1; loop >= 0; loop--)
-				key_put(klist->keys[loop]);
-
-			kfree(klist);
-		}
+		if (klist)
+			call_rcu(&klist->rcu, keyring_clear_rcu_disposal);
 
 		ret = 0;
 	}
diff --git a/security/keys/proc.c b/security/keys/proc.c
index 91343b85c39c..c55cf1fd0826 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -140,7 +140,7 @@ static int proc_keys_show(struct seq_file *m, void *v)
 
 	now = current_kernel_time();
 
-	read_lock(&key->lock);
+	rcu_read_lock();
 
 	/* come up with a suitable timeout value */
 	if (key->expiry == 0) {
@@ -164,14 +164,17 @@ static int proc_keys_show(struct seq_file *m, void *v)
 			sprintf(xbuf, "%luw", timo / (60*60*24*7));
 	}
 
+#define showflag(KEY, LETTER, FLAG) \
+	(test_bit(FLAG,	&(KEY)->flags) ? LETTER : '-')
+
 	seq_printf(m, "%08x %c%c%c%c%c%c %5d %4s %06x %5d %5d %-9.9s ",
 		   key->serial,
-		   key->flags & KEY_FLAG_INSTANTIATED	? 'I' : '-',
-		   key->flags & KEY_FLAG_REVOKED	? 'R' : '-',
-		   key->flags & KEY_FLAG_DEAD		? 'D' : '-',
-		   key->flags & KEY_FLAG_IN_QUOTA	? 'Q' : '-',
-		   key->flags & KEY_FLAG_USER_CONSTRUCT	? 'U' : '-',
-		   key->flags & KEY_FLAG_NEGATIVE	? 'N' : '-',
+		   showflag(key, 'I', KEY_FLAG_INSTANTIATED),
+		   showflag(key, 'R', KEY_FLAG_REVOKED),
+		   showflag(key, 'D', KEY_FLAG_DEAD),
+		   showflag(key, 'Q', KEY_FLAG_IN_QUOTA),
+		   showflag(key, 'U', KEY_FLAG_USER_CONSTRUCT),
+		   showflag(key, 'N', KEY_FLAG_NEGATIVE),
 		   atomic_read(&key->usage),
 		   xbuf,
 		   key->perm,
@@ -179,11 +182,13 @@ static int proc_keys_show(struct seq_file *m, void *v)
 		   key->gid,
 		   key->type->name);
 
+#undef showflag
+
 	if (key->type->describe)
 		key->type->describe(key, m);
 	seq_putc(m, '\n');
 
-	read_unlock(&key->lock);
+	rcu_read_unlock();
 
 	return 0;
 
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 2eb0e471cd40..9b0369c5a223 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -1,6 +1,6 @@
 /* process_keys.c: management of a process's keyrings
  *
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -38,10 +38,9 @@ struct key root_user_keyring = {
 	.serial		= 2,
 	.type		= &key_type_keyring,
 	.user		= &root_key_user,
-	.lock		= RW_LOCK_UNLOCKED,
 	.sem		= __RWSEM_INITIALIZER(root_user_keyring.sem),
 	.perm		= KEY_USR_ALL,
-	.flags		= KEY_FLAG_INSTANTIATED,
+	.flags		= 1 << KEY_FLAG_INSTANTIATED,
 	.description	= "_uid.0",
 #ifdef KEY_DEBUGGING
 	.magic		= KEY_DEBUG_MAGIC,
@@ -54,10 +53,9 @@ struct key root_session_keyring = {
 	.serial		= 1,
 	.type		= &key_type_keyring,
 	.user		= &root_key_user,
-	.lock		= RW_LOCK_UNLOCKED,
 	.sem		= __RWSEM_INITIALIZER(root_session_keyring.sem),
 	.perm		= KEY_USR_ALL,
-	.flags		= KEY_FLAG_INSTANTIATED,
+	.flags		= 1 << KEY_FLAG_INSTANTIATED,
 	.description	= "_uid_ses.0",
 #ifdef KEY_DEBUGGING
 	.magic		= KEY_DEBUG_MAGIC,
@@ -167,7 +165,7 @@ int install_thread_keyring(struct task_struct *tsk)
 /*
  * make sure a process keyring is installed
  */
-static int install_process_keyring(struct task_struct *tsk)
+int install_process_keyring(struct task_struct *tsk)
 {
 	unsigned long flags;
 	struct key *keyring;
@@ -183,7 +181,7 @@ static int install_process_keyring(struct task_struct *tsk)
 			goto error;
 		}
 
-		/* attach or swap keyrings */
+		/* attach keyring */
 		spin_lock_irqsave(&tsk->sighand->siglock, flags);
 		if (!tsk->signal->process_keyring) {
 			tsk->signal->process_keyring = keyring;
@@ -229,12 +227,14 @@ static int install_session_keyring(struct task_struct *tsk,
 
 	/* install the keyring */
 	spin_lock_irqsave(&tsk->sighand->siglock, flags);
-	old = tsk->signal->session_keyring;
-	tsk->signal->session_keyring = keyring;
+	old = rcu_dereference(tsk->signal->session_keyring);
+	rcu_assign_pointer(tsk->signal->session_keyring, keyring);
 	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
 
 	ret = 0;
 
+	/* we're using RCU on the pointer */
+	synchronize_rcu();
 	key_put(old);
  error:
 	return ret;
@@ -247,8 +247,6 @@ static int install_session_keyring(struct task_struct *tsk,
  */
 int copy_thread_group_keys(struct task_struct *tsk)
 {
-	unsigned long flags;
-
 	key_check(current->thread_group->session_keyring);
 	key_check(current->thread_group->process_keyring);
 
@@ -256,10 +254,10 @@ int copy_thread_group_keys(struct task_struct *tsk)
 	tsk->signal->process_keyring = NULL;
 
 	/* same session keyring */
-	spin_lock_irqsave(&current->sighand->siglock, flags);
+	rcu_read_lock();
 	tsk->signal->session_keyring =
-		key_get(current->signal->session_keyring);
-	spin_unlock_irqrestore(&current->sighand->siglock, flags);
+		key_get(rcu_dereference(current->signal->session_keyring));
+	rcu_read_unlock();
 
 	return 0;
 
@@ -349,9 +347,7 @@ void key_fsuid_changed(struct task_struct *tsk)
 	/* update the ownership of the thread keyring */
 	if (tsk->thread_keyring) {
 		down_write(&tsk->thread_keyring->sem);
-		write_lock(&tsk->thread_keyring->lock);
 		tsk->thread_keyring->uid = tsk->fsuid;
-		write_unlock(&tsk->thread_keyring->lock);
 		up_write(&tsk->thread_keyring->sem);
 	}
 
@@ -366,9 +362,7 @@ void key_fsgid_changed(struct task_struct *tsk)
 	/* update the ownership of the thread keyring */
 	if (tsk->thread_keyring) {
 		down_write(&tsk->thread_keyring->sem);
-		write_lock(&tsk->thread_keyring->lock);
 		tsk->thread_keyring->gid = tsk->fsgid;
-		write_unlock(&tsk->thread_keyring->lock);
 		up_write(&tsk->thread_keyring->sem);
 	}
 
@@ -382,13 +376,13 @@ void key_fsgid_changed(struct task_struct *tsk)
  * - we return -EAGAIN if we didn't find any matching key
  * - we return -ENOKEY if we found only negative matching keys
  */
-struct key *search_process_keyrings_aux(struct key_type *type,
-					const void *description,
-					key_match_func_t match)
+struct key *search_process_keyrings(struct key_type *type,
+				    const void *description,
+				    key_match_func_t match,
+				    struct task_struct *context)
 {
-	struct task_struct *tsk = current;
-	unsigned long flags;
-	struct key *key, *ret, *err, *tmp;
+	struct request_key_auth *rka;
+	struct key *key, *ret, *err, *instkey;
 
 	/* we want to return -EAGAIN or -ENOKEY if any of the keyrings were
 	 * searchable, but we failed to find a key or we found a negative key;
@@ -402,9 +396,9 @@ struct key *search_process_keyrings_aux(struct key_type *type,
 	err = ERR_PTR(-EAGAIN);
 
 	/* search the thread keyring first */
-	if (tsk->thread_keyring) {
-		key = keyring_search_aux(tsk->thread_keyring, type,
-					 description, match);
+	if (context->thread_keyring) {
+		key = keyring_search_aux(context->thread_keyring,
+					 context, type, description, match);
 		if (!IS_ERR(key))
 			goto found;
 
@@ -422,9 +416,9 @@ struct key *search_process_keyrings_aux(struct key_type *type,
 	}
 
 	/* search the process keyring second */
-	if (tsk->signal->process_keyring) {
-		key = keyring_search_aux(tsk->signal->process_keyring,
-					 type, description, match);
+	if (context->signal->process_keyring) {
+		key = keyring_search_aux(context->signal->process_keyring,
+					 context, type, description, match);
 		if (!IS_ERR(key))
 			goto found;
 
@@ -441,52 +435,93 @@ struct key *search_process_keyrings_aux(struct key_type *type,
 		}
 	}
 
-	/* search the session keyring last */
-	spin_lock_irqsave(&tsk->sighand->siglock, flags);
+	/* search the session keyring */
+	if (context->signal->session_keyring) {
+		rcu_read_lock();
+		key = keyring_search_aux(
+			rcu_dereference(context->signal->session_keyring),
+			context, type, description, match);
+		rcu_read_unlock();
 
-	tmp = tsk->signal->session_keyring;
-	if (!tmp)
-		tmp = tsk->user->session_keyring;
-	atomic_inc(&tmp->usage);
+		if (!IS_ERR(key))
+			goto found;
 
-	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+		switch (PTR_ERR(key)) {
+		case -EAGAIN: /* no key */
+			if (ret)
+				break;
+		case -ENOKEY: /* negative key */
+			ret = key;
+			break;
+		default:
+			err = key;
+			break;
+		}
+
+		/* if this process has a session keyring and that has an
+		 * instantiation authorisation key in the bottom level, then we
+		 * also search the keyrings of the process mentioned there */
+		if (context != current)
+			goto no_key;
+
+		rcu_read_lock();
+		instkey = __keyring_search_one(
+			rcu_dereference(context->signal->session_keyring),
+			&key_type_request_key_auth, NULL, 0);
+		rcu_read_unlock();
+
+		if (IS_ERR(instkey))
+			goto no_key;
+
+		rka = instkey->payload.data;
 
-	key = keyring_search_aux(tmp, type, description, match);
-	key_put(tmp);
-	if (!IS_ERR(key))
-		goto found;
+		key = search_process_keyrings(type, description, match,
+					      rka->context);
+		key_put(instkey);
 
-	switch (PTR_ERR(key)) {
-	case -EAGAIN: /* no key */
-		if (ret)
+		if (!IS_ERR(key))
+			goto found;
+
+		switch (PTR_ERR(key)) {
+		case -EAGAIN: /* no key */
+			if (ret)
+				break;
+		case -ENOKEY: /* negative key */
+			ret = key;
 			break;
-	case -ENOKEY: /* negative key */
-		ret = key;
-		break;
-	default:
-		err = key;
-		break;
+		default:
+			err = key;
+			break;
+		}
+	}
+	/* or search the user-session keyring */
+	else {
+		key = keyring_search_aux(context->user->session_keyring,
+					 context, type, description, match);
+		if (!IS_ERR(key))
+			goto found;
+
+		switch (PTR_ERR(key)) {
+		case -EAGAIN: /* no key */
+			if (ret)
+				break;
+		case -ENOKEY: /* negative key */
+			ret = key;
+			break;
+		default:
+			err = key;
+			break;
+		}
 	}
 
+
+no_key:
 	/* no key - decide on the error we're going to go for */
 	key = ret ? ret : err;
 
- found:
+found:
 	return key;
 
-} /* end search_process_keyrings_aux() */
-
-/*****************************************************************************/
-/*
- * search the process keyrings for the first matching key
- * - we return -EAGAIN if we didn't find any matching key
- * - we return -ENOKEY if we found only negative matching keys
- */
-struct key *search_process_keyrings(struct key_type *type,
-				    const char *description)
-{
-	return search_process_keyrings_aux(type, description, type->match);
-
 } /* end search_process_keyrings() */
 
 /*****************************************************************************/
@@ -495,72 +530,73 @@ struct key *search_process_keyrings(struct key_type *type,
  * - don't create special keyrings unless so requested
  * - partially constructed keys aren't found unless requested
  */
-struct key *lookup_user_key(key_serial_t id, int create, int partial,
-			    key_perm_t perm)
+struct key *lookup_user_key(struct task_struct *context, key_serial_t id,
+			    int create, int partial, key_perm_t perm)
 {
-	struct task_struct *tsk = current;
-	unsigned long flags;
 	struct key *key;
 	int ret;
 
+	if (!context)
+		context = current;
+
 	key = ERR_PTR(-ENOKEY);
 
 	switch (id) {
 	case KEY_SPEC_THREAD_KEYRING:
-		if (!tsk->thread_keyring) {
+		if (!context->thread_keyring) {
 			if (!create)
 				goto error;
 
-			ret = install_thread_keyring(tsk);
+			ret = install_thread_keyring(context);
 			if (ret < 0) {
 				key = ERR_PTR(ret);
 				goto error;
 			}
 		}
 
-		key = tsk->thread_keyring;
+		key = context->thread_keyring;
 		atomic_inc(&key->usage);
 		break;
 
 	case KEY_SPEC_PROCESS_KEYRING:
-		if (!tsk->signal->process_keyring) {
+		if (!context->signal->process_keyring) {
 			if (!create)
 				goto error;
 
-			ret = install_process_keyring(tsk);
+			ret = install_process_keyring(context);
 			if (ret < 0) {
 				key = ERR_PTR(ret);
 				goto error;
 			}
 		}
 
-		key = tsk->signal->process_keyring;
+		key = context->signal->process_keyring;
 		atomic_inc(&key->usage);
 		break;
 
 	case KEY_SPEC_SESSION_KEYRING:
-		if (!tsk->signal->session_keyring) {
+		if (!context->signal->session_keyring) {
 			/* always install a session keyring upon access if one
 			 * doesn't exist yet */
 			ret = install_session_keyring(
-			       tsk, tsk->user->session_keyring);
+			       context, context->user->session_keyring);
 			if (ret < 0)
 				goto error;
 		}
 
-		spin_lock_irqsave(&tsk->sighand->siglock, flags);
-		key = tsk->signal->session_keyring;
+		rcu_read_lock();
+		key = rcu_dereference(context->signal->session_keyring);
 		atomic_inc(&key->usage);
-		spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+		rcu_read_unlock();
 		break;
 
 	case KEY_SPEC_USER_KEYRING:
-		key = tsk->user->uid_keyring;
+		key = context->user->uid_keyring;
 		atomic_inc(&key->usage);
 		break;
 
 	case KEY_SPEC_USER_SESSION_KEYRING:
-		key = tsk->user->session_keyring;
+		key = context->user->session_keyring;
 		atomic_inc(&key->usage);
 		break;
 
@@ -580,7 +616,7 @@ struct key *lookup_user_key(key_serial_t id, int create, int partial,
 		break;
 	}
 
-	/* check the status and permissions */
+	/* check the status */
 	if (perm) {
 		ret = key_validate(key);
 		if (ret < 0)
@@ -588,11 +624,13 @@ struct key *lookup_user_key(key_serial_t id, int create, int partial,
 	}
 
 	ret = -EIO;
-	if (!partial && !(key->flags & KEY_FLAG_INSTANTIATED))
+	if (!partial && !test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
 		goto invalid_key;
 
+	/* check the permissions */
 	ret = -EACCES;
-	if (!key_permission(key, perm))
+
+	if (!key_task_permission(key, context, perm))
 		goto invalid_key;
 
  error:
@@ -615,7 +653,6 @@ struct key *lookup_user_key(key_serial_t id, int create, int partial,
 long join_session_keyring(const char *name)
 {
 	struct task_struct *tsk = current;
-	unsigned long flags;
 	struct key *keyring;
 	long ret;
 
@@ -625,9 +662,9 @@ long join_session_keyring(const char *name)
 		if (ret < 0)
 			goto error;
 
-		spin_lock_irqsave(&tsk->sighand->siglock, flags);
-		ret = tsk->signal->session_keyring->serial;
-		spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
+		rcu_read_lock();
+		ret = rcu_dereference(tsk->signal->session_keyring)->serial;
+		rcu_read_unlock();
 		goto error;
 	}
 
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 9705b1aeba5d..dfcd983af1fd 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -1,6 +1,6 @@
 /* request_key.c: request a key from userspace
  *
- * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2004-5 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  *
  * This program is free software; you can redistribute it and/or
@@ -13,6 +13,7 @@
 #include <linux/sched.h>
 #include <linux/kmod.h>
 #include <linux/err.h>
+#include <linux/keyctl.h>
 #include "internal.h"
 
 struct key_construction {
@@ -27,18 +28,26 @@ DECLARE_WAIT_QUEUE_HEAD(request_key_conswq);
 /*
  * request userspace finish the construction of a key
  * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring> <info>"
- * - if callout_info is an empty string, it'll be rendered as a "-" instead
  */
 static int call_request_key(struct key *key,
 			    const char *op,
 			    const char *callout_info)
 {
 	struct task_struct *tsk = current;
-	unsigned long flags;
 	key_serial_t prkey, sskey;
+	struct key *session_keyring, *rkakey;
 	char *argv[10], *envp[3], uid_str[12], gid_str[12];
 	char key_str[12], keyring_str[3][12];
-	int i;
+	int ret, i;
+
+	kenter("{%d},%s,%s", key->serial, op, callout_info);
+
+	/* generate a new session keyring with an auth key in it */
+	session_keyring = request_key_auth_new(key, &rkakey);
+	if (IS_ERR(session_keyring)) {
+		ret = PTR_ERR(session_keyring);
+		goto error;
+	}
 
 	/* record the UID and GID */
 	sprintf(uid_str, "%d", current->fsuid);
@@ -55,17 +64,17 @@ static int call_request_key(struct key *key,
 	if (tsk->signal->process_keyring)
 		prkey = tsk->signal->process_keyring->serial;
 
-	sskey = 0;
-	spin_lock_irqsave(&tsk->sighand->siglock, flags);
-	if (tsk->signal->session_keyring)
-		sskey = tsk->signal->session_keyring->serial;
-	spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
-
+	sprintf(keyring_str[1], "%d", prkey);
 
-	if (!sskey)
+	if (tsk->signal->session_keyring) {
+		rcu_read_lock();
+		sskey = rcu_dereference(tsk->signal->session_keyring)->serial;
+		rcu_read_unlock();
+	}
+	else {
 		sskey = tsk->user->session_keyring->serial;
+	}
 
-	sprintf(keyring_str[1], "%d", prkey);
 	sprintf(keyring_str[2], "%d", sskey);
 
 	/* set up a minimal environment */
@@ -84,11 +93,20 @@ static int call_request_key(struct key *key,
 	argv[i++] = keyring_str[0];
 	argv[i++] = keyring_str[1];
 	argv[i++] = keyring_str[2];
-	argv[i++] = callout_info[0] ? (char *) callout_info : "-";
+	argv[i++] = (char *) callout_info;
 	argv[i] = NULL;
 
 	/* do it */
-	return call_usermodehelper(argv[0], argv, envp, 1);
+	ret = call_usermodehelper_keys(argv[0], argv, envp, session_keyring, 1);
+
+	/* dispose of the special keys */
+	key_revoke(rkakey);
+	key_put(rkakey);
+	key_put(session_keyring);
+
+ error:
+	kleave(" = %d", ret);
+	return ret;
 
 } /* end call_request_key() */
 
@@ -105,7 +123,9 @@ static struct key *__request_key_construction(struct key_type *type,
 	struct key_construction cons;
 	struct timespec now;
 	struct key *key;
-	int ret, negative;
+	int ret, negated;
+
+	kenter("%s,%s,%s", type->name, description, callout_info);
 
 	/* create a key and add it to the queue */
 	key = key_alloc(type, description,
@@ -113,9 +133,7 @@ static struct key *__request_key_construction(struct key_type *type,
 	if (IS_ERR(key))
 		goto alloc_failed;
 
-	write_lock(&key->lock);
-	key->flags |= KEY_FLAG_USER_CONSTRUCT;
-	write_unlock(&key->lock);
+	set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
 
 	cons.key = key;
 	list_add_tail(&cons.link, &key->user->consq);
@@ -130,7 +148,7 @@ static struct key *__request_key_construction(struct key_type *type,
 
 	/* if the key wasn't instantiated, then we want to give an error */
 	ret = -ENOKEY;
-	if (!(key->flags & KEY_FLAG_INSTANTIATED))
+	if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags))
 		goto request_failed;
 
 	down_write(&key_construction_sem);
@@ -139,12 +157,13 @@ static struct key *__request_key_construction(struct key_type *type,
 
 	/* also give an error if the key was negatively instantiated */
  check_not_negative:
-	if (key->flags & KEY_FLAG_NEGATIVE) {
+	if (test_bit(KEY_FLAG_NEGATIVE, &key->flags)) {
 		key_put(key);
 		key = ERR_PTR(-ENOKEY);
 	}
 
  out:
+	kleave(" = %p", key);
 	return key;
 
  request_failed:
@@ -152,24 +171,23 @@ static struct key *__request_key_construction(struct key_type *type,
 	 * - remove from construction queue
 	 * - mark the key as dead
 	 */
-	negative = 0;
+	negated = 0;
 	down_write(&key_construction_sem);
 
 	list_del(&cons.link);
 
-	write_lock(&key->lock);
-	key->flags &= ~KEY_FLAG_USER_CONSTRUCT;
-
 	/* check it didn't get instantiated between the check and the down */
-	if (!(key->flags & KEY_FLAG_INSTANTIATED)) {
-		key->flags |= KEY_FLAG_INSTANTIATED | KEY_FLAG_NEGATIVE;
-		negative = 1;
+	if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
+		set_bit(KEY_FLAG_NEGATIVE, &key->flags);
+		set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
+		negated = 1;
 	}
 
-	write_unlock(&key->lock);
+	clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
+
 	up_write(&key_construction_sem);
 
-	if (!negative)
+	if (!negated)
 		goto check_not_negative; /* surprisingly, the key got
 					  * instantiated */
 
@@ -178,13 +196,12 @@ static struct key *__request_key_construction(struct key_type *type,
 	key->expiry = now.tv_sec + key_negative_timeout;
 
 	if (current->signal->session_keyring) {
-		unsigned long flags;
 		struct key *keyring;
 
-		spin_lock_irqsave(&current->sighand->siglock, flags);
-		keyring = current->signal->session_keyring;
+		rcu_read_lock();
+		keyring = rcu_dereference(current->signal->session_keyring);
 		atomic_inc(&keyring->usage);
-		spin_unlock_irqrestore(&current->sighand->siglock, flags);
+		rcu_read_unlock();
 
 		key_link(keyring, key);
 		key_put(keyring);
@@ -220,6 +237,9 @@ static struct key *request_key_construction(struct key_type *type,
 
 	DECLARE_WAITQUEUE(myself, current);
 
+	kenter("%s,%s,{%d},%s",
+	       type->name, description, user->uid, callout_info);
+
 	/* see if there's such a key under construction already */
 	down_write(&key_construction_sem);
 
@@ -236,6 +256,7 @@ static struct key *request_key_construction(struct key_type *type,
 	/* see about getting userspace to construct the key */
 	key = __request_key_construction(type, description, callout_info);
  error:
+	kleave(" = %p", key);
 	return key;
 
 	/* someone else has the same key under construction
@@ -249,8 +270,10 @@ static struct key *request_key_construction(struct key_type *type,
 	add_wait_queue(&request_key_conswq, &myself);
 
 	for (;;) {
-		set_current_state(TASK_UNINTERRUPTIBLE);
-		if (!(ckey->flags & KEY_FLAG_USER_CONSTRUCT))
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (!test_bit(KEY_FLAG_USER_CONSTRUCT, &ckey->flags))
+			break;
+		if (signal_pending(current))
 			break;
 		schedule();
 	}
@@ -271,21 +294,83 @@ static struct key *request_key_construction(struct key_type *type,
 
 /*****************************************************************************/
 /*
+ * link a freshly minted key to an appropriate destination keyring
+ */
+static void request_key_link(struct key *key, struct key *dest_keyring)
+{
+	struct task_struct *tsk = current;
+	struct key *drop = NULL;
+
+	kenter("{%d},%p", key->serial, dest_keyring);
+
+	/* find the appropriate keyring */
+	if (!dest_keyring) {
+		switch (tsk->jit_keyring) {
+		case KEY_REQKEY_DEFL_DEFAULT:
+		case KEY_REQKEY_DEFL_THREAD_KEYRING:
+			dest_keyring = tsk->thread_keyring;
+			if (dest_keyring)
+				break;
+
+		case KEY_REQKEY_DEFL_PROCESS_KEYRING:
+			dest_keyring = tsk->signal->process_keyring;
+			if (dest_keyring)
+				break;
+
+		case KEY_REQKEY_DEFL_SESSION_KEYRING:
+			rcu_read_lock();
+			dest_keyring = key_get(
+				rcu_dereference(tsk->signal->session_keyring));
+			rcu_read_unlock();
+			drop = dest_keyring;
+
+			if (dest_keyring)
+				break;
+
+		case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
+			dest_keyring = current->user->session_keyring;
+			break;
+
+		case KEY_REQKEY_DEFL_USER_KEYRING:
+			dest_keyring = current->user->uid_keyring;
+			break;
+
+		case KEY_REQKEY_DEFL_GROUP_KEYRING:
+		default:
+			BUG();
+		}
+	}
+
+	/* and attach the key to it */
+	key_link(dest_keyring, key);
+
+	key_put(drop);
+
+	kleave("");
+
+} /* end request_key_link() */
+
+/*****************************************************************************/
+/*
  * request a key
  * - search the process's keyrings
  * - check the list of keys being created or updated
- * - call out to userspace for a key if requested (supplementary info can be
- *   passed)
+ * - call out to userspace for a key if supplementary info was provided
+ * - cache the key in an appropriate keyring
  */
-struct key *request_key(struct key_type *type,
-			const char *description,
-			const char *callout_info)
+struct key *request_key_and_link(struct key_type *type,
+				 const char *description,
+				 const char *callout_info,
+				 struct key *dest_keyring)
 {
 	struct key_user *user;
 	struct key *key;
 
+	kenter("%s,%s,%s,%p",
+	       type->name, description, callout_info, dest_keyring);
+
 	/* search all the process keyrings for a key */
-	key = search_process_keyrings_aux(type, description, type->match);
+	key = search_process_keyrings(type, description, type->match, current);
 
 	if (PTR_ERR(key) == -EAGAIN) {
 		/* the search failed, but the keyrings were searchable, so we
@@ -296,12 +381,13 @@ struct key *request_key(struct key_type *type,
 
 		/* - get hold of the user's construction queue */
 		user = key_user_lookup(current->fsuid);
-		if (!user) {
-			key = ERR_PTR(-ENOMEM);
-			goto error;
-		}
+		if (!user)
+			goto nomem;
+
+		do {
+			if (signal_pending(current))
+				goto interrupted;
 
-		for (;;) {
 			/* ask userspace (returns NULL if it waited on a key
 			 * being constructed) */
 			key = request_key_construction(type, description,
@@ -311,18 +397,46 @@ struct key *request_key(struct key_type *type,
 
 			/* someone else made the key we want, so we need to
 			 * search again as it might now be available to us */
-			key = search_process_keyrings_aux(type, description,
-							  type->match);
-			if (PTR_ERR(key) != -EAGAIN)
-				break;
-		}
+			key = search_process_keyrings(type, description,
+						      type->match, current);
+
+		} while (PTR_ERR(key) == -EAGAIN);
 
 		key_user_put(user);
+
+		/* link the new key into the appropriate keyring */
+		if (!PTR_ERR(key))
+			request_key_link(key, dest_keyring);
 	}
 
- error:
+error:
+	kleave(" = %p", key);
 	return key;
 
+nomem:
+	key = ERR_PTR(-ENOMEM);
+	goto error;
+
+interrupted:
+	key_user_put(user);
+	key = ERR_PTR(-EINTR);
+	goto error;
+
+} /* end request_key_and_link() */
+
+/*****************************************************************************/
+/*
+ * request a key
+ * - search the process's keyrings
+ * - check the list of keys being created or updated
+ * - call out to userspace for a key if supplementary info was provided
+ */
+struct key *request_key(struct key_type *type,
+			const char *description,
+			const char *callout_info)
+{
+	return request_key_and_link(type, description, callout_info, NULL);
+
 } /* end request_key() */
 
 EXPORT_SYMBOL(request_key);
@@ -339,7 +453,8 @@ int key_validate(struct key *key)
 	if (key) {
 		/* check it's still accessible */
 		ret = -EKEYREVOKED;
-		if (key->flags & (KEY_FLAG_REVOKED | KEY_FLAG_DEAD))
+		if (test_bit(KEY_FLAG_REVOKED, &key->flags) ||
+		    test_bit(KEY_FLAG_DEAD, &key->flags))
 			goto error;
 
 		/* check it hasn't expired */
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
new file mode 100644
index 000000000000..f22264632229
--- /dev/null
+++ b/security/keys/request_key_auth.c
@@ -0,0 +1,180 @@
+/* request_key_auth.c: request key authorisation controlling key def
+ *
+ * Copyright (C) 2005 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/seq_file.h>
+#include "internal.h"
+
+static int request_key_auth_instantiate(struct key *, const void *, size_t);
+static void request_key_auth_describe(const struct key *, struct seq_file *);
+static void request_key_auth_destroy(struct key *);
+
+/*
+ * the request-key authorisation key type definition
+ */
+struct key_type key_type_request_key_auth = {
+	.name		= ".request_key_auth",
+	.def_datalen	= sizeof(struct request_key_auth),
+	.instantiate	= request_key_auth_instantiate,
+	.describe	= request_key_auth_describe,
+	.destroy	= request_key_auth_destroy,
+};
+
+/*****************************************************************************/
+/*
+ * instantiate a request-key authorisation record
+ */
+static int request_key_auth_instantiate(struct key *key,
+					const void *data,
+					size_t datalen)
+{
+	struct request_key_auth *rka, *irka;
+	struct key *instkey;
+	int ret;
+
+	ret = -ENOMEM;
+	rka = kmalloc(sizeof(*rka), GFP_KERNEL);
+	if (rka) {
+		/* see if the calling process is already servicing the key
+		 * request of another process */
+		instkey = key_get_instantiation_authkey(0);
+		if (!IS_ERR(instkey)) {
+			/* it is - use that instantiation context here too */
+			irka = instkey->payload.data;
+			rka->context = irka->context;
+			rka->pid = irka->pid;
+			key_put(instkey);
+		}
+		else {
+			/* it isn't - use this process as the context */
+			rka->context = current;
+			rka->pid = current->pid;
+		}
+
+		rka->target_key = key_get((struct key *) data);
+		key->payload.data = rka;
+		ret = 0;
+	}
+
+	return ret;
+
+} /* end request_key_auth_instantiate() */
+
+/*****************************************************************************/
+/*
+ *
+ */
+static void request_key_auth_describe(const struct key *key,
+				      struct seq_file *m)
+{
+	struct request_key_auth *rka = key->payload.data;
+
+	seq_puts(m, "key:");
+	seq_puts(m, key->description);
+	seq_printf(m, " pid:%d", rka->pid);
+
+} /* end request_key_auth_describe() */
+
+/*****************************************************************************/
+/*
+ * destroy an instantiation authorisation token key
+ */
+static void request_key_auth_destroy(struct key *key)
+{
+	struct request_key_auth *rka = key->payload.data;
+
+	kenter("{%d}", key->serial);
+
+	key_put(rka->target_key);
+
+} /* end request_key_auth_destroy() */
+
+/*****************************************************************************/
+/*
+ * create a session keyring to be for the invokation of /sbin/request-key and
+ * stick an authorisation token in it
+ */
+struct key *request_key_auth_new(struct key *target, struct key **_rkakey)
+{
+	struct key *keyring, *rkakey = NULL;
+	char desc[20];
+	int ret;
+
+	kenter("%d,", target->serial);
+
+	/* allocate a new session keyring */
+	sprintf(desc, "_req.%u", target->serial);
+
+	keyring = keyring_alloc(desc, current->fsuid, current->fsgid, 1, NULL);
+	if (IS_ERR(keyring)) {
+		kleave("= %ld", PTR_ERR(keyring));
+		return keyring;
+	}
+
+	/* allocate the auth key */
+	sprintf(desc, "%x", target->serial);
+
+	rkakey = key_alloc(&key_type_request_key_auth, desc,
+			   current->fsuid, current->fsgid,
+			   KEY_USR_VIEW, 1);
+	if (IS_ERR(rkakey)) {
+		key_put(keyring);
+		kleave("= %ld", PTR_ERR(rkakey));
+		return rkakey;
+	}
+
+	/* construct and attach to the keyring */
+	ret = key_instantiate_and_link(rkakey, target, 0, keyring, NULL);
+	if (ret < 0) {
+		key_revoke(rkakey);
+		key_put(rkakey);
+		key_put(keyring);
+		kleave("= %d", ret);
+		return ERR_PTR(ret);
+	}
+
+	*_rkakey = rkakey;
+	kleave(" = {%d} ({%d})", keyring->serial, rkakey->serial);
+	return keyring;
+
+} /* end request_key_auth_new() */
+
+/*****************************************************************************/
+/*
+ * get the authorisation key for instantiation of a specific key if attached to
+ * the current process's keyrings
+ * - this key is inserted into a keyring and that is set as /sbin/request-key's
+ *   session keyring
+ * - a target_id of zero specifies any valid token
+ */
+struct key *key_get_instantiation_authkey(key_serial_t target_id)
+{
+	struct task_struct *tsk = current;
+	struct key *instkey;
+
+	/* we must have our own personal session keyring */
+	if (!tsk->signal->session_keyring)
+		return ERR_PTR(-EACCES);
+
+	/* and it must contain a suitable request authorisation key
+	 * - lock RCU against session keyring changing
+	 */
+	rcu_read_lock();
+
+	instkey = keyring_search_instkey(
+		rcu_dereference(tsk->signal->session_keyring), target_id);
+
+	rcu_read_unlock();
+	return instkey;
+
+} /* end key_get_instantiation_authkey() */
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index 8d65b3a28129..e446acba73d3 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -42,12 +42,21 @@ struct key_type key_type_user = {
 	.read		= user_read,
 };
 
+struct user_key_payload {
+	struct rcu_head	rcu;		/* RCU destructor */
+	unsigned short	datalen;	/* length of this data */
+	char		data[0];	/* actual data */
+};
+
+EXPORT_SYMBOL_GPL(key_type_user);
+
 /*****************************************************************************/
 /*
  * instantiate a user defined key
  */
 static int user_instantiate(struct key *key, const void *data, size_t datalen)
 {
+	struct user_key_payload *upayload;
 	int ret;
 
 	ret = -EINVAL;
@@ -58,13 +67,15 @@ static int user_instantiate(struct key *key, const void *data, size_t datalen)
 	if (ret < 0)
 		goto error;
 
-	/* attach the data */
 	ret = -ENOMEM;
-	key->payload.data = kmalloc(datalen, GFP_KERNEL);
-	if (!key->payload.data)
+	upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
+	if (!upayload)
 		goto error;
 
-	memcpy(key->payload.data, data, datalen);
+	/* attach the data */
+	upayload->datalen = datalen;
+	memcpy(upayload->data, data, datalen);
+	rcu_assign_pointer(key->payload.data, upayload);
 	ret = 0;
 
  error:
@@ -75,18 +86,25 @@ static int user_instantiate(struct key *key, const void *data, size_t datalen)
 /*****************************************************************************/
 /*
  * duplicate a user defined key
+ * - both keys' semaphores are locked against further modification
+ * - the new key cannot yet be accessed
  */
 static int user_duplicate(struct key *key, const struct key *source)
 {
+	struct user_key_payload *upayload, *spayload;
 	int ret;
 
 	/* just copy the payload */
 	ret = -ENOMEM;
-	key->payload.data = kmalloc(source->datalen, GFP_KERNEL);
+	upayload = kmalloc(sizeof(*upayload) + source->datalen, GFP_KERNEL);
+	if (upayload) {
+		spayload = rcu_dereference(source->payload.data);
+		BUG_ON(source->datalen != spayload->datalen);
+
+		upayload->datalen = key->datalen = spayload->datalen;
+		memcpy(upayload->data, spayload->data, key->datalen);
 
-	if (key->payload.data) {
-		key->datalen = source->datalen;
-		memcpy(key->payload.data, source->payload.data, source->datalen);
+		key->payload.data = upayload;
 		ret = 0;
 	}
 
@@ -96,40 +114,54 @@ static int user_duplicate(struct key *key, const struct key *source)
 
 /*****************************************************************************/
 /*
+ * dispose of the old data from an updated user defined key
+ */
+static void user_update_rcu_disposal(struct rcu_head *rcu)
+{
+	struct user_key_payload *upayload;
+
+	upayload = container_of(rcu, struct user_key_payload, rcu);
+
+	kfree(upayload);
+
+} /* end user_update_rcu_disposal() */
+
+/*****************************************************************************/
+/*
  * update a user defined key
+ * - the key's semaphore is write-locked
  */
 static int user_update(struct key *key, const void *data, size_t datalen)
 {
-	void *new, *zap;
+	struct user_key_payload *upayload, *zap;
 	int ret;
 
 	ret = -EINVAL;
 	if (datalen <= 0 || datalen > 32767 || !data)
 		goto error;
 
-	/* copy the data */
+	/* construct a replacement payload */
 	ret = -ENOMEM;
-	new = kmalloc(datalen, GFP_KERNEL);
-	if (!new)
+	upayload = kmalloc(sizeof(*upayload) + datalen, GFP_KERNEL);
+	if (!upayload)
 		goto error;
 
-	memcpy(new, data, datalen);
+	upayload->datalen = datalen;
+	memcpy(upayload->data, data, datalen);
 
 	/* check the quota and attach the new data */
-	zap = new;
-	write_lock(&key->lock);
+	zap = upayload;
 
 	ret = key_payload_reserve(key, datalen);
 
 	if (ret == 0) {
 		/* attach the new data, displacing the old */
 		zap = key->payload.data;
-		key->payload.data = new;
+		rcu_assign_pointer(key->payload.data, upayload);
 		key->expiry = 0;
 	}
 
-	write_unlock(&key->lock);
-	kfree(zap);
+	call_rcu(&zap->rcu, user_update_rcu_disposal);
 
  error:
 	return ret;
@@ -152,13 +184,15 @@ static int user_match(const struct key *key, const void *description)
  */
 static void user_destroy(struct key *key)
 {
-	kfree(key->payload.data);
+	struct user_key_payload *upayload = key->payload.data;
+
+	kfree(upayload);
 
 } /* end user_destroy() */
 
 /*****************************************************************************/
 /*
- * describe the user
+ * describe the user key
  */
 static void user_describe(const struct key *key, struct seq_file *m)
 {
@@ -171,18 +205,23 @@ static void user_describe(const struct key *key, struct seq_file *m)
 /*****************************************************************************/
 /*
  * read the key data
+ * - the key's semaphore is read-locked
  */
 static long user_read(const struct key *key,
 		      char __user *buffer, size_t buflen)
 {
-	long ret = key->datalen;
+	struct user_key_payload *upayload;
+	long ret;
+
+	upayload = rcu_dereference(key->payload.data);
+	ret = upayload->datalen;
 
 	/* we can return the data as is */
 	if (buffer && buflen > 0) {
-		if (buflen > key->datalen)
-			buflen = key->datalen;
+		if (buflen > upayload->datalen)
+			buflen = upayload->datalen;
 
-		if (copy_to_user(buffer, key->payload.data, buflen) != 0)
+		if (copy_to_user(buffer, upayload->data, buflen) != 0)
 			ret = -EFAULT;
 	}