--- /dev/null
+From foo@baz Mon Nov 7 10:07:26 AM CET 2022
+From: Eric Biggers <ebiggers@kernel.org>
+Date: Fri, 4 Nov 2022 16:37:59 -0700
+Subject: fscrypt: stop using keyrings subsystem for fscrypt_master_key
+To: stable@vger.kernel.org
+Cc: linux-fscrypt@vger.kernel.org
+Message-ID: <20221104233800.421135-3-ebiggers@kernel.org>
+
+From: Eric Biggers <ebiggers@google.com>
+
+commit d7e7b9af104c7b389a0c21eb26532511bce4b510 upstream.
+
+The approach of fs/crypto/ internally managing the fscrypt_master_key
+structs as the payloads of "struct key" objects contained in a
+"struct key" keyring has outlived its usefulness. The original idea was
+to simplify the code by reusing code from the keyrings subsystem.
+However, several issues have arisen that can't easily be resolved:
+
+- When a master key struct is destroyed, blk_crypto_evict_key() must be
+ called on any per-mode keys embedded in it. (This started being the
+ case when inline encryption support was added.) Yet, the keyrings
+ subsystem can arbitrarily delay the destruction of keys, even past the
+ time the filesystem was unmounted. Therefore, currently there is no
+ easy way to call blk_crypto_evict_key() when a master key is
+ destroyed. Currently, this is worked around by holding an extra
+ reference to the filesystem's request_queue(s). But it was overlooked
+ that the request_queue reference is *not* guaranteed to pin the
+ corresponding blk_crypto_profile too; for device-mapper devices that
+ support inline crypto, it doesn't. This can cause a use-after-free.
+
+- When the last inode that was using an incompletely-removed master key
+ is evicted, the master key removal is completed by removing the key
+ struct from the keyring. Currently this is done via key_invalidate().
+ Yet, key_invalidate() takes the key semaphore. This can deadlock when
+ called from the shrinker, since in fscrypt_ioctl_add_key(), memory is
+ allocated with GFP_KERNEL under the same semaphore.
+
+- More generally, the fact that the keyrings subsystem can arbitrarily
+ delay the destruction of keys (via garbage collection delay, or via
+ random processes getting temporary key references) is undesirable, as
+ it means we can't strictly guarantee that all secrets are ever wiped.
+
+- Doing the master key lookups via the keyrings subsystem results in the
+ key_permission LSM hook being called. fscrypt doesn't want this, as
+ all access control for encrypted files is designed to happen via the
+ files themselves, like any other files. The workaround which SELinux
+ users are using is to change their SELinux policy to grant key search
+ access to all domains. This works, but it is an odd extra step that
+ shouldn't really have to be done.
+
+The fix for all these issues is to change the implementation to what I
+should have done originally: don't use the keyrings subsystem to keep
+track of the filesystem's fscrypt_master_key structs. Instead, just
+store them in a regular kernel data structure, and rework the reference
+counting, locking, and lifetime accordingly. Retain support for
+RCU-mode key lookups by using a hash table. Replace fscrypt_sb_free()
+with fscrypt_sb_delete(), which releases the keys synchronously and runs
+a bit earlier during unmount, so that block devices are still available.
+
+A side effect of this patch is that neither the master keys themselves
+nor the filesystem keyrings will be listed in /proc/keys anymore.
+("Master key users" and the master key users keyrings will still be
+listed.) However, this was mostly an implementation detail, and it was
+intended just for debugging purposes. I don't know of anyone using it.
+
+This patch does *not* change how "master key users" (->mk_users) works;
+that still uses the keyrings subsystem. That is still needed for key
+quotas, and changing that isn't necessary to solve the issues listed
+above. If we decide to change that too, it would be a separate patch.
+
+I've marked this as fixing the original commit that added the fscrypt
+keyring, but as noted above the most important issue that this patch
+fixes wasn't introduced until the addition of inline encryption support.
+
+Fixes: 22d94f493bfb ("fscrypt: add FS_IOC_ADD_ENCRYPTION_KEY ioctl")
+Signed-off-by: Eric Biggers <ebiggers@google.com>
+Link: https://lore.kernel.org/r/20220901193208.138056-2-ebiggers@kernel.org
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/crypto/fscrypt_private.h | 71 ++++--
+ fs/crypto/hooks.c | 10
+ fs/crypto/keyring.c | 484 +++++++++++++++++++++++---------------------
+ fs/crypto/keysetup.c | 81 ++-----
+ fs/crypto/policy.c | 8
+ fs/super.c | 2
+ include/linux/fs.h | 2
+ include/linux/fscrypt.h | 4
+ 8 files changed, 352 insertions(+), 310 deletions(-)
+
+--- a/fs/crypto/fscrypt_private.h
++++ b/fs/crypto/fscrypt_private.h
+@@ -220,7 +220,7 @@ struct fscrypt_info {
+ * will be NULL if the master key was found in a process-subscribed
+ * keyring rather than in the filesystem-level keyring.
+ */
+- struct key *ci_master_key;
++ struct fscrypt_master_key *ci_master_key;
+
+ /*
+ * Link in list of inodes that were unlocked with the master key.
+@@ -432,6 +432,40 @@ struct fscrypt_master_key_secret {
+ struct fscrypt_master_key {
+
+ /*
++ * Back-pointer to the super_block of the filesystem to which this
++ * master key has been added. Only valid if ->mk_active_refs > 0.
++ */
++ struct super_block *mk_sb;
++
++ /*
++ * Link in ->mk_sb->s_master_keys->key_hashtable.
++ * Only valid if ->mk_active_refs > 0.
++ */
++ struct hlist_node mk_node;
++
++ /* Semaphore that protects ->mk_secret and ->mk_users */
++ struct rw_semaphore mk_sem;
++
++ /*
++ * Active and structural reference counts. An active ref guarantees
++ * that the struct continues to exist, continues to be in the keyring
++ * ->mk_sb->s_master_keys, and that any embedded subkeys (e.g.
++ * ->mk_direct_keys) that have been prepared continue to exist.
++ * A structural ref only guarantees that the struct continues to exist.
++ *
++ * There is one active ref associated with ->mk_secret being present,
++ * and one active ref for each inode in ->mk_decrypted_inodes.
++ *
++ * There is one structural ref associated with the active refcount being
++ * nonzero. Finding a key in the keyring also takes a structural ref,
++ * which is then held temporarily while the key is operated on.
++ */
++ refcount_t mk_active_refs;
++ refcount_t mk_struct_refs;
++
++ struct rcu_head mk_rcu_head;
++
++ /*
+ * The secret key material. After FS_IOC_REMOVE_ENCRYPTION_KEY is
+ * executed, this is wiped and no new inodes can be unlocked with this
+ * key; however, there may still be inodes in ->mk_decrypted_inodes
+@@ -439,7 +473,10 @@ struct fscrypt_master_key {
+ * FS_IOC_REMOVE_ENCRYPTION_KEY can be retried, or
+ * FS_IOC_ADD_ENCRYPTION_KEY can add the secret again.
+ *
+- * Locking: protected by this master key's key->sem.
++ * While ->mk_secret is present, one ref in ->mk_active_refs is held.
++ *
++ * Locking: protected by ->mk_sem. The manipulation of ->mk_active_refs
++ * associated with this field is protected by ->mk_sem as well.
+ */
+ struct fscrypt_master_key_secret mk_secret;
+
+@@ -460,23 +497,13 @@ struct fscrypt_master_key {
+ *
+ * This is NULL for v1 policy keys; those can only be added by root.
+ *
+- * Locking: in addition to this keyring's own semaphore, this is
+- * protected by this master key's key->sem, so we can do atomic
+- * search+insert. It can also be searched without taking any locks, but
+- * in that case the returned key may have already been removed.
++ * Locking: protected by ->mk_sem. (We don't just rely on the keyrings
++ * subsystem semaphore ->mk_users->sem, as we need support for atomic
++ * search+insert along with proper synchronization with ->mk_secret.)
+ */
+ struct key *mk_users;
+
+ /*
+- * Length of ->mk_decrypted_inodes, plus one if mk_secret is present.
+- * Once this goes to 0, the master key is removed from ->s_master_keys.
+- * The 'struct fscrypt_master_key' will continue to live as long as the
+- * 'struct key' whose payload it is, but we won't let this reference
+- * count rise again.
+- */
+- refcount_t mk_refcount;
+-
+- /*
+ * List of inodes that were unlocked using this key. This allows the
+ * inodes to be evicted efficiently if the key is removed.
+ */
+@@ -501,10 +528,10 @@ static inline bool
+ is_master_key_secret_present(const struct fscrypt_master_key_secret *secret)
+ {
+ /*
+- * The READ_ONCE() is only necessary for fscrypt_drop_inode() and
+- * fscrypt_key_describe(). These run in atomic context, so they can't
+- * take the key semaphore and thus 'secret' can change concurrently
+- * which would be a data race. But they only need to know whether the
++ * The READ_ONCE() is only necessary for fscrypt_drop_inode().
++ * fscrypt_drop_inode() runs in atomic context, so it can't take the key
++ * semaphore and thus 'secret' can change concurrently which would be a
++ * data race. But fscrypt_drop_inode() only need to know whether the
+ * secret *was* present at the time of check, so READ_ONCE() suffices.
+ */
+ return READ_ONCE(secret->size) != 0;
+@@ -533,7 +560,11 @@ static inline int master_key_spec_len(co
+ return 0;
+ }
+
+-struct key *
++void fscrypt_put_master_key(struct fscrypt_master_key *mk);
++
++void fscrypt_put_master_key_activeref(struct fscrypt_master_key *mk);
++
++struct fscrypt_master_key *
+ fscrypt_find_master_key(struct super_block *sb,
+ const struct fscrypt_key_specifier *mk_spec);
+
+--- a/fs/crypto/hooks.c
++++ b/fs/crypto/hooks.c
+@@ -5,8 +5,6 @@
+ * Encryption hooks for higher-level filesystem operations.
+ */
+
+-#include <linux/key.h>
+-
+ #include "fscrypt_private.h"
+
+ /**
+@@ -139,7 +137,6 @@ int fscrypt_prepare_setflags(struct inod
+ unsigned int oldflags, unsigned int flags)
+ {
+ struct fscrypt_info *ci;
+- struct key *key;
+ struct fscrypt_master_key *mk;
+ int err;
+
+@@ -155,14 +152,13 @@ int fscrypt_prepare_setflags(struct inod
+ ci = inode->i_crypt_info;
+ if (ci->ci_policy.version != FSCRYPT_POLICY_V2)
+ return -EINVAL;
+- key = ci->ci_master_key;
+- mk = key->payload.data[0];
+- down_read(&key->sem);
++ mk = ci->ci_master_key;
++ down_read(&mk->mk_sem);
+ if (is_master_key_secret_present(&mk->mk_secret))
+ err = fscrypt_derive_dirhash_key(ci, mk);
+ else
+ err = -ENOKEY;
+- up_read(&key->sem);
++ up_read(&mk->mk_sem);
+ return err;
+ }
+ return 0;
+--- a/fs/crypto/keyring.c
++++ b/fs/crypto/keyring.c
+@@ -18,6 +18,7 @@
+ * information about these ioctls.
+ */
+
++#include <asm/unaligned.h>
+ #include <crypto/skcipher.h>
+ #include <linux/key-type.h>
+ #include <linux/random.h>
+@@ -25,6 +26,18 @@
+
+ #include "fscrypt_private.h"
+
++/* The master encryption keys for a filesystem (->s_master_keys) */
++struct fscrypt_keyring {
++ /*
++ * Lock that protects ->key_hashtable. It does *not* protect the
++ * fscrypt_master_key structs themselves.
++ */
++ spinlock_t lock;
++
++ /* Hash table that maps fscrypt_key_specifier to fscrypt_master_key */
++ struct hlist_head key_hashtable[128];
++};
++
+ static void wipe_master_key_secret(struct fscrypt_master_key_secret *secret)
+ {
+ fscrypt_destroy_hkdf(&secret->hkdf);
+@@ -38,20 +51,70 @@ static void move_master_key_secret(struc
+ memzero_explicit(src, sizeof(*src));
+ }
+
+-static void free_master_key(struct fscrypt_master_key *mk)
++static void fscrypt_free_master_key(struct rcu_head *head)
++{
++ struct fscrypt_master_key *mk =
++ container_of(head, struct fscrypt_master_key, mk_rcu_head);
++ /*
++ * The master key secret and any embedded subkeys should have already
++ * been wiped when the last active reference to the fscrypt_master_key
++ * struct was dropped; doing it here would be unnecessarily late.
++ * Nevertheless, use kfree_sensitive() in case anything was missed.
++ */
++ kfree_sensitive(mk);
++}
++
++void fscrypt_put_master_key(struct fscrypt_master_key *mk)
++{
++ if (!refcount_dec_and_test(&mk->mk_struct_refs))
++ return;
++ /*
++ * No structural references left, so free ->mk_users, and also free the
++ * fscrypt_master_key struct itself after an RCU grace period ensures
++ * that concurrent keyring lookups can no longer find it.
++ */
++ WARN_ON(refcount_read(&mk->mk_active_refs) != 0);
++ key_put(mk->mk_users);
++ mk->mk_users = NULL;
++ call_rcu(&mk->mk_rcu_head, fscrypt_free_master_key);
++}
++
++void fscrypt_put_master_key_activeref(struct fscrypt_master_key *mk)
+ {
++ struct super_block *sb = mk->mk_sb;
++ struct fscrypt_keyring *keyring = sb->s_master_keys;
+ size_t i;
+
+- wipe_master_key_secret(&mk->mk_secret);
++ if (!refcount_dec_and_test(&mk->mk_active_refs))
++ return;
++ /*
++ * No active references left, so complete the full removal of this
++ * fscrypt_master_key struct by removing it from the keyring and
++ * destroying any subkeys embedded in it.
++ */
++
++ spin_lock(&keyring->lock);
++ hlist_del_rcu(&mk->mk_node);
++ spin_unlock(&keyring->lock);
++
++ /*
++ * ->mk_active_refs == 0 implies that ->mk_secret is not present and
++ * that ->mk_decrypted_inodes is empty.
++ */
++ WARN_ON(is_master_key_secret_present(&mk->mk_secret));
++ WARN_ON(!list_empty(&mk->mk_decrypted_inodes));
+
+ for (i = 0; i <= FSCRYPT_MODE_MAX; i++) {
+ fscrypt_destroy_prepared_key(&mk->mk_direct_keys[i]);
+ fscrypt_destroy_prepared_key(&mk->mk_iv_ino_lblk_64_keys[i]);
+ fscrypt_destroy_prepared_key(&mk->mk_iv_ino_lblk_32_keys[i]);
+ }
++ memzero_explicit(&mk->mk_ino_hash_key,
++ sizeof(mk->mk_ino_hash_key));
++ mk->mk_ino_hash_key_initialized = false;
+
+- key_put(mk->mk_users);
+- kfree_sensitive(mk);
++ /* Drop the structural ref associated with the active refs. */
++ fscrypt_put_master_key(mk);
+ }
+
+ static inline bool valid_key_spec(const struct fscrypt_key_specifier *spec)
+@@ -61,44 +124,6 @@ static inline bool valid_key_spec(const
+ return master_key_spec_len(spec) != 0;
+ }
+
+-static int fscrypt_key_instantiate(struct key *key,
+- struct key_preparsed_payload *prep)
+-{
+- key->payload.data[0] = (struct fscrypt_master_key *)prep->data;
+- return 0;
+-}
+-
+-static void fscrypt_key_destroy(struct key *key)
+-{
+- free_master_key(key->payload.data[0]);
+-}
+-
+-static void fscrypt_key_describe(const struct key *key, struct seq_file *m)
+-{
+- seq_puts(m, key->description);
+-
+- if (key_is_positive(key)) {
+- const struct fscrypt_master_key *mk = key->payload.data[0];
+-
+- if (!is_master_key_secret_present(&mk->mk_secret))
+- seq_puts(m, ": secret removed");
+- }
+-}
+-
+-/*
+- * Type of key in ->s_master_keys. Each key of this type represents a master
+- * key which has been added to the filesystem. Its payload is a
+- * 'struct fscrypt_master_key'. The "." prefix in the key type name prevents
+- * users from adding keys of this type via the keyrings syscalls rather than via
+- * the intended method of FS_IOC_ADD_ENCRYPTION_KEY.
+- */
+-static struct key_type key_type_fscrypt = {
+- .name = "._fscrypt",
+- .instantiate = fscrypt_key_instantiate,
+- .destroy = fscrypt_key_destroy,
+- .describe = fscrypt_key_describe,
+-};
+-
+ static int fscrypt_user_key_instantiate(struct key *key,
+ struct key_preparsed_payload *prep)
+ {
+@@ -131,32 +156,6 @@ static struct key_type key_type_fscrypt_
+ .describe = fscrypt_user_key_describe,
+ };
+
+-/* Search ->s_master_keys or ->mk_users */
+-static struct key *search_fscrypt_keyring(struct key *keyring,
+- struct key_type *type,
+- const char *description)
+-{
+- /*
+- * We need to mark the keyring reference as "possessed" so that we
+- * acquire permission to search it, via the KEY_POS_SEARCH permission.
+- */
+- key_ref_t keyref = make_key_ref(keyring, true /* possessed */);
+-
+- keyref = keyring_search(keyref, type, description, false);
+- if (IS_ERR(keyref)) {
+- if (PTR_ERR(keyref) == -EAGAIN || /* not found */
+- PTR_ERR(keyref) == -EKEYREVOKED) /* recently invalidated */
+- keyref = ERR_PTR(-ENOKEY);
+- return ERR_CAST(keyref);
+- }
+- return key_ref_to_ptr(keyref);
+-}
+-
+-#define FSCRYPT_FS_KEYRING_DESCRIPTION_SIZE \
+- (CONST_STRLEN("fscrypt-") + sizeof_field(struct super_block, s_id))
+-
+-#define FSCRYPT_MK_DESCRIPTION_SIZE (2 * FSCRYPT_KEY_IDENTIFIER_SIZE + 1)
+-
+ #define FSCRYPT_MK_USERS_DESCRIPTION_SIZE \
+ (CONST_STRLEN("fscrypt-") + 2 * FSCRYPT_KEY_IDENTIFIER_SIZE + \
+ CONST_STRLEN("-users") + 1)
+@@ -164,21 +163,6 @@ static struct key *search_fscrypt_keyrin
+ #define FSCRYPT_MK_USER_DESCRIPTION_SIZE \
+ (2 * FSCRYPT_KEY_IDENTIFIER_SIZE + CONST_STRLEN(".uid.") + 10 + 1)
+
+-static void format_fs_keyring_description(
+- char description[FSCRYPT_FS_KEYRING_DESCRIPTION_SIZE],
+- const struct super_block *sb)
+-{
+- sprintf(description, "fscrypt-%s", sb->s_id);
+-}
+-
+-static void format_mk_description(
+- char description[FSCRYPT_MK_DESCRIPTION_SIZE],
+- const struct fscrypt_key_specifier *mk_spec)
+-{
+- sprintf(description, "%*phN",
+- master_key_spec_len(mk_spec), (u8 *)&mk_spec->u);
+-}
+-
+ static void format_mk_users_keyring_description(
+ char description[FSCRYPT_MK_USERS_DESCRIPTION_SIZE],
+ const u8 mk_identifier[FSCRYPT_KEY_IDENTIFIER_SIZE])
+@@ -199,20 +183,15 @@ static void format_mk_user_description(
+ /* Create ->s_master_keys if needed. Synchronized by fscrypt_add_key_mutex. */
+ static int allocate_filesystem_keyring(struct super_block *sb)
+ {
+- char description[FSCRYPT_FS_KEYRING_DESCRIPTION_SIZE];
+- struct key *keyring;
++ struct fscrypt_keyring *keyring;
+
+ if (sb->s_master_keys)
+ return 0;
+
+- format_fs_keyring_description(description, sb);
+- keyring = keyring_alloc(description, GLOBAL_ROOT_UID, GLOBAL_ROOT_GID,
+- current_cred(), KEY_POS_SEARCH |
+- KEY_USR_SEARCH | KEY_USR_READ | KEY_USR_VIEW,
+- KEY_ALLOC_NOT_IN_QUOTA, NULL, NULL);
+- if (IS_ERR(keyring))
+- return PTR_ERR(keyring);
+-
++ keyring = kzalloc(sizeof(*keyring), GFP_KERNEL);
++ if (!keyring)
++ return -ENOMEM;
++ spin_lock_init(&keyring->lock);
+ /*
+ * Pairs with the smp_load_acquire() in fscrypt_find_master_key().
+ * I.e., here we publish ->s_master_keys with a RELEASE barrier so that
+@@ -222,21 +201,75 @@ static int allocate_filesystem_keyring(s
+ return 0;
+ }
+
+-void fscrypt_sb_free(struct super_block *sb)
++/*
++ * This is called at unmount time to release all encryption keys that have been
++ * added to the filesystem, along with the keyring that contains them.
++ *
++ * Note that besides clearing and freeing memory, this might need to evict keys
++ * from the keyslots of an inline crypto engine. Therefore, this must be called
++ * while the filesystem's underlying block device(s) are still available.
++ */
++void fscrypt_sb_delete(struct super_block *sb)
+ {
+- key_put(sb->s_master_keys);
++ struct fscrypt_keyring *keyring = sb->s_master_keys;
++ size_t i;
++
++ if (!keyring)
++ return;
++
++ for (i = 0; i < ARRAY_SIZE(keyring->key_hashtable); i++) {
++ struct hlist_head *bucket = &keyring->key_hashtable[i];
++ struct fscrypt_master_key *mk;
++ struct hlist_node *tmp;
++
++ hlist_for_each_entry_safe(mk, tmp, bucket, mk_node) {
++ /*
++ * Since all inodes were already evicted, every key
++ * remaining in the keyring should have an empty inode
++ * list, and should only still be in the keyring due to
++ * the single active ref associated with ->mk_secret.
++ * There should be no structural refs beyond the one
++ * associated with the active ref.
++ */
++ WARN_ON(refcount_read(&mk->mk_active_refs) != 1);
++ WARN_ON(refcount_read(&mk->mk_struct_refs) != 1);
++ WARN_ON(!is_master_key_secret_present(&mk->mk_secret));
++ wipe_master_key_secret(&mk->mk_secret);
++ fscrypt_put_master_key_activeref(mk);
++ }
++ }
++ kfree_sensitive(keyring);
+ sb->s_master_keys = NULL;
+ }
+
++static struct hlist_head *
++fscrypt_mk_hash_bucket(struct fscrypt_keyring *keyring,
++ const struct fscrypt_key_specifier *mk_spec)
++{
++ /*
++ * Since key specifiers should be "random" values, it is sufficient to
++ * use a trivial hash function that just takes the first several bits of
++ * the key specifier.
++ */
++ unsigned long i = get_unaligned((unsigned long *)&mk_spec->u);
++
++ return &keyring->key_hashtable[i % ARRAY_SIZE(keyring->key_hashtable)];
++}
++
+ /*
+- * Find the specified master key in ->s_master_keys.
+- * Returns ERR_PTR(-ENOKEY) if not found.
++ * Find the specified master key struct in ->s_master_keys and take a structural
++ * ref to it. The structural ref guarantees that the key struct continues to
++ * exist, but it does *not* guarantee that ->s_master_keys continues to contain
++ * the key struct. The structural ref needs to be dropped by
++ * fscrypt_put_master_key(). Returns NULL if the key struct is not found.
+ */
+-struct key *fscrypt_find_master_key(struct super_block *sb,
+- const struct fscrypt_key_specifier *mk_spec)
++struct fscrypt_master_key *
++fscrypt_find_master_key(struct super_block *sb,
++ const struct fscrypt_key_specifier *mk_spec)
+ {
+- struct key *keyring;
+- char description[FSCRYPT_MK_DESCRIPTION_SIZE];
++ struct fscrypt_keyring *keyring;
++ struct hlist_head *bucket;
++ struct fscrypt_master_key *mk;
+
+ /*
+ * Pairs with the smp_store_release() in allocate_filesystem_keyring().
+@@ -246,10 +279,38 @@ struct key *fscrypt_find_master_key(stru
+ */
+ keyring = smp_load_acquire(&sb->s_master_keys);
+ if (keyring == NULL)
+- return ERR_PTR(-ENOKEY); /* No keyring yet, so no keys yet. */
++ return NULL; /* No keyring yet, so no keys yet. */
+
+- format_mk_description(description, mk_spec);
+- return search_fscrypt_keyring(keyring, &key_type_fscrypt, description);
++ bucket = fscrypt_mk_hash_bucket(keyring, mk_spec);
++ rcu_read_lock();
++ switch (mk_spec->type) {
++ case FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR:
++ hlist_for_each_entry_rcu(mk, bucket, mk_node) {
++ if (mk->mk_spec.type ==
++ FSCRYPT_KEY_SPEC_TYPE_DESCRIPTOR &&
++ memcmp(mk->mk_spec.u.descriptor,
++ mk_spec->u.descriptor,
++ FSCRYPT_KEY_DESCRIPTOR_SIZE) == 0 &&
++ refcount_inc_not_zero(&mk->mk_struct_refs))
++ goto out;
++ }
++ break;
++ case FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER:
++ hlist_for_each_entry_rcu(mk, bucket, mk_node) {
++ if (mk->mk_spec.type ==
++ FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER &&
++ memcmp(mk->mk_spec.u.identifier,
++ mk_spec->u.identifier,
++ FSCRYPT_KEY_IDENTIFIER_SIZE) == 0 &&
++ refcount_inc_not_zero(&mk->mk_struct_refs))
++ goto out;
++ }
++ break;
++ }
++ mk = NULL;
++out:
++ rcu_read_unlock();
++ return mk;
+ }
+
+ static int allocate_master_key_users_keyring(struct fscrypt_master_key *mk)
+@@ -277,17 +338,30 @@ static int allocate_master_key_users_key
+ static struct key *find_master_key_user(struct fscrypt_master_key *mk)
+ {
+ char description[FSCRYPT_MK_USER_DESCRIPTION_SIZE];
++ key_ref_t keyref;
+
+ format_mk_user_description(description, mk->mk_spec.u.identifier);
+- return search_fscrypt_keyring(mk->mk_users, &key_type_fscrypt_user,
+- description);
++
++ /*
++ * We need to mark the keyring reference as "possessed" so that we
++ * acquire permission to search it, via the KEY_POS_SEARCH permission.
++ */
++ keyref = keyring_search(make_key_ref(mk->mk_users, true /*possessed*/),
++ &key_type_fscrypt_user, description, false);
++ if (IS_ERR(keyref)) {
++ if (PTR_ERR(keyref) == -EAGAIN || /* not found */
++ PTR_ERR(keyref) == -EKEYREVOKED) /* recently invalidated */
++ keyref = ERR_PTR(-ENOKEY);
++ return ERR_CAST(keyref);
++ }
++ return key_ref_to_ptr(keyref);
+ }
+
+ /*
+ * Give the current user a "key" in ->mk_users. This charges the user's quota
+ * and marks the master key as added by the current user, so that it cannot be
+- * removed by another user with the key. Either the master key's key->sem must
+- * be held for write, or the master key must be still undergoing initialization.
++ * removed by another user with the key. Either ->mk_sem must be held for
++ * write, or the master key must be still undergoing initialization.
+ */
+ static int add_master_key_user(struct fscrypt_master_key *mk)
+ {
+@@ -309,7 +383,7 @@ static int add_master_key_user(struct fs
+
+ /*
+ * Remove the current user's "key" from ->mk_users.
+- * The master key's key->sem must be held for write.
++ * ->mk_sem must be held for write.
+ *
+ * Returns 0 if removed, -ENOKEY if not found, or another -errno code.
+ */
+@@ -327,63 +401,49 @@ static int remove_master_key_user(struct
+ }
+
+ /*
+- * Allocate a new fscrypt_master_key which contains the given secret, set it as
+- * the payload of a new 'struct key' of type fscrypt, and link the 'struct key'
+- * into the given keyring. Synchronized by fscrypt_add_key_mutex.
++ * Allocate a new fscrypt_master_key, transfer the given secret over to it, and
++ * insert it into sb->s_master_keys.
+ */
+-static int add_new_master_key(struct fscrypt_master_key_secret *secret,
+- const struct fscrypt_key_specifier *mk_spec,
+- struct key *keyring)
++static int add_new_master_key(struct super_block *sb,
++ struct fscrypt_master_key_secret *secret,
++ const struct fscrypt_key_specifier *mk_spec)
+ {
++ struct fscrypt_keyring *keyring = sb->s_master_keys;
+ struct fscrypt_master_key *mk;
+- char description[FSCRYPT_MK_DESCRIPTION_SIZE];
+- struct key *key;
+ int err;
+
+ mk = kzalloc(sizeof(*mk), GFP_KERNEL);
+ if (!mk)
+ return -ENOMEM;
+
++ mk->mk_sb = sb;
++ init_rwsem(&mk->mk_sem);
++ refcount_set(&mk->mk_struct_refs, 1);
+ mk->mk_spec = *mk_spec;
+
+- move_master_key_secret(&mk->mk_secret, secret);
+-
+- refcount_set(&mk->mk_refcount, 1); /* secret is present */
+ INIT_LIST_HEAD(&mk->mk_decrypted_inodes);
+ spin_lock_init(&mk->mk_decrypted_inodes_lock);
+
+ if (mk_spec->type == FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER) {
+ err = allocate_master_key_users_keyring(mk);
+ if (err)
+- goto out_free_mk;
++ goto out_put;
+ err = add_master_key_user(mk);
+ if (err)
+- goto out_free_mk;
++ goto out_put;
+ }
+
+- /*
+- * Note that we don't charge this key to anyone's quota, since when
+- * ->mk_users is in use those keys are charged instead, and otherwise
+- * (when ->mk_users isn't in use) only root can add these keys.
+- */
+- format_mk_description(description, mk_spec);
+- key = key_alloc(&key_type_fscrypt, description,
+- GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, current_cred(),
+- KEY_POS_SEARCH | KEY_USR_SEARCH | KEY_USR_VIEW,
+- KEY_ALLOC_NOT_IN_QUOTA, NULL);
+- if (IS_ERR(key)) {
+- err = PTR_ERR(key);
+- goto out_free_mk;
+- }
+- err = key_instantiate_and_link(key, mk, sizeof(*mk), keyring, NULL);
+- key_put(key);
+- if (err)
+- goto out_free_mk;
++ move_master_key_secret(&mk->mk_secret, secret);
++ refcount_set(&mk->mk_active_refs, 1); /* ->mk_secret is present */
+
++ spin_lock(&keyring->lock);
++ hlist_add_head_rcu(&mk->mk_node,
++ fscrypt_mk_hash_bucket(keyring, mk_spec));
++ spin_unlock(&keyring->lock);
+ return 0;
+
+-out_free_mk:
+- free_master_key(mk);
++out_put:
++ fscrypt_put_master_key(mk);
+ return err;
+ }
+
+@@ -392,42 +452,34 @@ out_free_mk:
+ static int add_existing_master_key(struct fscrypt_master_key *mk,
+ struct fscrypt_master_key_secret *secret)
+ {
+- struct key *mk_user;
+- bool rekey;
+ int err;
+
+ /*
+ * If the current user is already in ->mk_users, then there's nothing to
+- * do. (Not applicable for v1 policy keys, which have NULL ->mk_users.)
++ * do. Otherwise, we need to add the user to ->mk_users. (Neither is
++ * applicable for v1 policy keys, which have NULL ->mk_users.)
+ */
+ if (mk->mk_users) {
+- mk_user = find_master_key_user(mk);
++ struct key *mk_user = find_master_key_user(mk);
++
+ if (mk_user != ERR_PTR(-ENOKEY)) {
+ if (IS_ERR(mk_user))
+ return PTR_ERR(mk_user);
+ key_put(mk_user);
+ return 0;
+ }
+- }
+-
+- /* If we'll be re-adding ->mk_secret, try to take the reference. */
+- rekey = !is_master_key_secret_present(&mk->mk_secret);
+- if (rekey && !refcount_inc_not_zero(&mk->mk_refcount))
+- return KEY_DEAD;
+-
+- /* Add the current user to ->mk_users, if applicable. */
+- if (mk->mk_users) {
+ err = add_master_key_user(mk);
+- if (err) {
+- if (rekey && refcount_dec_and_test(&mk->mk_refcount))
+- return KEY_DEAD;
++ if (err)
+ return err;
+- }
+ }
+
+ /* Re-add the secret if needed. */
+- if (rekey)
++ if (!is_master_key_secret_present(&mk->mk_secret)) {
++ if (!refcount_inc_not_zero(&mk->mk_active_refs))
++ return KEY_DEAD;
+ move_master_key_secret(&mk->mk_secret, secret);
++ }
++
+ return 0;
+ }
+
+@@ -436,38 +488,36 @@ static int do_add_master_key(struct supe
+ const struct fscrypt_key_specifier *mk_spec)
+ {
+ static DEFINE_MUTEX(fscrypt_add_key_mutex);
+- struct key *key;
++ struct fscrypt_master_key *mk;
+ int err;
+
+ mutex_lock(&fscrypt_add_key_mutex); /* serialize find + link */
+-retry:
+- key = fscrypt_find_master_key(sb, mk_spec);
+- if (IS_ERR(key)) {
+- err = PTR_ERR(key);
+- if (err != -ENOKEY)
+- goto out_unlock;
++
++ mk = fscrypt_find_master_key(sb, mk_spec);
++ if (!mk) {
+ /* Didn't find the key in ->s_master_keys. Add it. */
+ err = allocate_filesystem_keyring(sb);
+- if (err)
+- goto out_unlock;
+- err = add_new_master_key(secret, mk_spec, sb->s_master_keys);
++ if (!err)
++ err = add_new_master_key(sb, secret, mk_spec);
+ } else {
+ /*
+ * Found the key in ->s_master_keys. Re-add the secret if
+ * needed, and add the user to ->mk_users if needed.
+ */
+- down_write(&key->sem);
+- err = add_existing_master_key(key->payload.data[0], secret);
+- up_write(&key->sem);
++ down_write(&mk->mk_sem);
++ err = add_existing_master_key(mk, secret);
++ up_write(&mk->mk_sem);
+ if (err == KEY_DEAD) {
+- /* Key being removed or needs to be removed */
+- key_invalidate(key);
+- key_put(key);
+- goto retry;
++ /*
++ * We found a key struct, but it's already been fully
++ * removed. Ignore the old struct and add a new one.
++ * fscrypt_add_key_mutex means we don't need to worry
++ * about concurrent adds.
++ */
++ err = add_new_master_key(sb, secret, mk_spec);
+ }
+- key_put(key);
++ fscrypt_put_master_key(mk);
+ }
+-out_unlock:
+ mutex_unlock(&fscrypt_add_key_mutex);
+ return err;
+ }
+@@ -731,19 +781,19 @@ int fscrypt_verify_key_added(struct supe
+ const u8 identifier[FSCRYPT_KEY_IDENTIFIER_SIZE])
+ {
+ struct fscrypt_key_specifier mk_spec;
+- struct key *key, *mk_user;
+ struct fscrypt_master_key *mk;
++ struct key *mk_user;
+ int err;
+
+ mk_spec.type = FSCRYPT_KEY_SPEC_TYPE_IDENTIFIER;
+ memcpy(mk_spec.u.identifier, identifier, FSCRYPT_KEY_IDENTIFIER_SIZE);
+
+- key = fscrypt_find_master_key(sb, &mk_spec);
+- if (IS_ERR(key)) {
+- err = PTR_ERR(key);
++ mk = fscrypt_find_master_key(sb, &mk_spec);
++ if (!mk) {
++ err = -ENOKEY;
+ goto out;
+ }
+- mk = key->payload.data[0];
++ down_read(&mk->mk_sem);
+ mk_user = find_master_key_user(mk);
+ if (IS_ERR(mk_user)) {
+ err = PTR_ERR(mk_user);
+@@ -751,7 +801,8 @@ int fscrypt_verify_key_added(struct supe
+ key_put(mk_user);
+ err = 0;
+ }
+- key_put(key);
++ up_read(&mk->mk_sem);
++ fscrypt_put_master_key(mk);
+ out:
+ if (err == -ENOKEY && capable(CAP_FOWNER))
+ err = 0;
+@@ -913,11 +964,10 @@ static int do_remove_key(struct file *fi
+ struct super_block *sb = file_inode(filp)->i_sb;
+ struct fscrypt_remove_key_arg __user *uarg = _uarg;
+ struct fscrypt_remove_key_arg arg;
+- struct key *key;
+ struct fscrypt_master_key *mk;
+ u32 status_flags = 0;
+ int err;
+- bool dead;
++ bool inodes_remain;
+
+ if (copy_from_user(&arg, uarg, sizeof(arg)))
+ return -EFAULT;
+@@ -937,12 +987,10 @@ static int do_remove_key(struct file *fi
+ return -EACCES;
+
+ /* Find the key being removed. */
+- key = fscrypt_find_master_key(sb, &arg.key_spec);
+- if (IS_ERR(key))
+- return PTR_ERR(key);
+- mk = key->payload.data[0];
+-
+- down_write(&key->sem);
++ mk = fscrypt_find_master_key(sb, &arg.key_spec);
++ if (!mk)
++ return -ENOKEY;
++ down_write(&mk->mk_sem);
+
+ /* If relevant, remove current user's (or all users) claim to the key */
+ if (mk->mk_users && mk->mk_users->keys.nr_leaves_on_tree != 0) {
+@@ -951,7 +999,7 @@ static int do_remove_key(struct file *fi
+ else
+ err = remove_master_key_user(mk);
+ if (err) {
+- up_write(&key->sem);
++ up_write(&mk->mk_sem);
+ goto out_put_key;
+ }
+ if (mk->mk_users->keys.nr_leaves_on_tree != 0) {
+@@ -963,26 +1011,22 @@ static int do_remove_key(struct file *fi
+ status_flags |=
+ FSCRYPT_KEY_REMOVAL_STATUS_FLAG_OTHER_USERS;
+ err = 0;
+- up_write(&key->sem);
++ up_write(&mk->mk_sem);
+ goto out_put_key;
+ }
+ }
+
+ /* No user claims remaining. Go ahead and wipe the secret. */
+- dead = false;
++ err = -ENOKEY;
+ if (is_master_key_secret_present(&mk->mk_secret)) {
+ wipe_master_key_secret(&mk->mk_secret);
+- dead = refcount_dec_and_test(&mk->mk_refcount);
+- }
+- up_write(&key->sem);
+- if (dead) {
+- /*
+- * No inodes reference the key, and we wiped the secret, so the
+- * key object is free to be removed from the keyring.
+- */
+- key_invalidate(key);
++ fscrypt_put_master_key_activeref(mk);
+ err = 0;
+- } else {
++ }
++ inodes_remain = refcount_read(&mk->mk_active_refs) > 0;
++ up_write(&mk->mk_sem);
++
++ if (inodes_remain) {
+ /* Some inodes still reference this key; try to evict them. */
+ err = try_to_lock_encrypted_files(sb, mk);
+ if (err == -EBUSY) {
+@@ -998,7 +1042,7 @@ static int do_remove_key(struct file *fi
+ * has been fully removed including all files locked.
+ */
+ out_put_key:
+- key_put(key);
++ fscrypt_put_master_key(mk);
+ if (err == 0)
+ err = put_user(status_flags, &uarg->removal_status_flags);
+ return err;
+@@ -1045,7 +1089,6 @@ int fscrypt_ioctl_get_key_status(struct
+ {
+ struct super_block *sb = file_inode(filp)->i_sb;
+ struct fscrypt_get_key_status_arg arg;
+- struct key *key;
+ struct fscrypt_master_key *mk;
+ int err;
+
+@@ -1062,19 +1105,18 @@ int fscrypt_ioctl_get_key_status(struct
+ arg.user_count = 0;
+ memset(arg.__out_reserved, 0, sizeof(arg.__out_reserved));
+
+- key = fscrypt_find_master_key(sb, &arg.key_spec);
+- if (IS_ERR(key)) {
+- if (key != ERR_PTR(-ENOKEY))
+- return PTR_ERR(key);
++ mk = fscrypt_find_master_key(sb, &arg.key_spec);
++ if (!mk) {
+ arg.status = FSCRYPT_KEY_STATUS_ABSENT;
+ err = 0;
+ goto out;
+ }
+- mk = key->payload.data[0];
+- down_read(&key->sem);
++ down_read(&mk->mk_sem);
+
+ if (!is_master_key_secret_present(&mk->mk_secret)) {
+- arg.status = FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED;
++ arg.status = refcount_read(&mk->mk_active_refs) > 0 ?
++ FSCRYPT_KEY_STATUS_INCOMPLETELY_REMOVED :
++ FSCRYPT_KEY_STATUS_ABSENT /* raced with full removal */;
+ err = 0;
+ goto out_release_key;
+ }
+@@ -1096,8 +1138,8 @@ int fscrypt_ioctl_get_key_status(struct
+ }
+ err = 0;
+ out_release_key:
+- up_read(&key->sem);
+- key_put(key);
++ up_read(&mk->mk_sem);
++ fscrypt_put_master_key(mk);
+ out:
+ if (!err && copy_to_user(uarg, &arg, sizeof(arg)))
+ err = -EFAULT;
+@@ -1109,13 +1151,9 @@ int __init fscrypt_init_keyring(void)
+ {
+ int err;
+
+- err = register_key_type(&key_type_fscrypt);
+- if (err)
+- return err;
+-
+ err = register_key_type(&key_type_fscrypt_user);
+ if (err)
+- goto err_unregister_fscrypt;
++ return err;
+
+ err = register_key_type(&key_type_fscrypt_provisioning);
+ if (err)
+@@ -1125,7 +1163,5 @@ int __init fscrypt_init_keyring(void)
+
+ err_unregister_fscrypt_user:
+ unregister_key_type(&key_type_fscrypt_user);
+-err_unregister_fscrypt:
+- unregister_key_type(&key_type_fscrypt);
+ return err;
+ }
+--- a/fs/crypto/keysetup.c
++++ b/fs/crypto/keysetup.c
+@@ -9,7 +9,6 @@
+ */
+
+ #include <crypto/skcipher.h>
+-#include <linux/key.h>
+ #include <linux/random.h>
+
+ #include "fscrypt_private.h"
+@@ -151,6 +150,7 @@ void fscrypt_destroy_prepared_key(struct
+ {
+ crypto_free_skcipher(prep_key->tfm);
+ fscrypt_destroy_inline_crypt_key(prep_key);
++ memzero_explicit(prep_key, sizeof(*prep_key));
+ }
+
+ /* Given a per-file encryption key, set up the file's crypto transform object */
+@@ -404,20 +404,18 @@ static bool fscrypt_valid_master_key_siz
+ /*
+ * Find the master key, then set up the inode's actual encryption key.
+ *
+- * If the master key is found in the filesystem-level keyring, then the
+- * corresponding 'struct key' is returned in *master_key_ret with its semaphore
+- * read-locked. This is needed to ensure that only one task links the
+- * fscrypt_info into ->mk_decrypted_inodes (as multiple tasks may race to create
+- * an fscrypt_info for the same inode), and to synchronize the master key being
+- * removed with a new inode starting to use it.
++ * If the master key is found in the filesystem-level keyring, then it is
++ * returned in *mk_ret with its semaphore read-locked. This is needed to ensure
++ * that only one task links the fscrypt_info into ->mk_decrypted_inodes (as
++ * multiple tasks may race to create an fscrypt_info for the same inode), and to
++ * synchronize the master key being removed with a new inode starting to use it.
+ */
+ static int setup_file_encryption_key(struct fscrypt_info *ci,
+ bool need_dirhash_key,
+- struct key **master_key_ret)
++ struct fscrypt_master_key **mk_ret)
+ {
+- struct key *key;
+- struct fscrypt_master_key *mk = NULL;
+ struct fscrypt_key_specifier mk_spec;
++ struct fscrypt_master_key *mk;
+ int err;
+
+ err = fscrypt_select_encryption_impl(ci);
+@@ -442,11 +440,10 @@ static int setup_file_encryption_key(str
+ return -EINVAL;
+ }
+
+- key = fscrypt_find_master_key(ci->ci_inode->i_sb, &mk_spec);
+- if (IS_ERR(key)) {
+- if (key != ERR_PTR(-ENOKEY) ||
+- ci->ci_policy.version != FSCRYPT_POLICY_V1)
+- return PTR_ERR(key);
++ mk = fscrypt_find_master_key(ci->ci_inode->i_sb, &mk_spec);
++ if (!mk) {
++ if (ci->ci_policy.version != FSCRYPT_POLICY_V1)
++ return -ENOKEY;
+
+ /*
+ * As a legacy fallback for v1 policies, search for the key in
+@@ -456,9 +453,7 @@ static int setup_file_encryption_key(str
+ */
+ return fscrypt_setup_v1_file_key_via_subscribed_keyrings(ci);
+ }
+-
+- mk = key->payload.data[0];
+- down_read(&key->sem);
++ down_read(&mk->mk_sem);
+
+ /* Has the secret been removed (via FS_IOC_REMOVE_ENCRYPTION_KEY)? */
+ if (!is_master_key_secret_present(&mk->mk_secret)) {
+@@ -486,18 +481,18 @@ static int setup_file_encryption_key(str
+ if (err)
+ goto out_release_key;
+
+- *master_key_ret = key;
++ *mk_ret = mk;
+ return 0;
+
+ out_release_key:
+- up_read(&key->sem);
+- key_put(key);
++ up_read(&mk->mk_sem);
++ fscrypt_put_master_key(mk);
+ return err;
+ }
+
+ static void put_crypt_info(struct fscrypt_info *ci)
+ {
+- struct key *key;
++ struct fscrypt_master_key *mk;
+
+ if (!ci)
+ return;
+@@ -507,24 +502,18 @@ static void put_crypt_info(struct fscryp
+ else if (ci->ci_owns_key)
+ fscrypt_destroy_prepared_key(&ci->ci_enc_key);
+
+- key = ci->ci_master_key;
+- if (key) {
+- struct fscrypt_master_key *mk = key->payload.data[0];
+-
++ mk = ci->ci_master_key;
++ if (mk) {
+ /*
+ * Remove this inode from the list of inodes that were unlocked
+- * with the master key.
+- *
+- * In addition, if we're removing the last inode from a key that
+- * already had its secret removed, invalidate the key so that it
+- * gets removed from ->s_master_keys.
++ * with the master key. In addition, if we're removing the last
++ * inode from a master key struct that already had its secret
++ * removed, then complete the full removal of the struct.
+ */
+ spin_lock(&mk->mk_decrypted_inodes_lock);
+ list_del(&ci->ci_master_key_link);
+ spin_unlock(&mk->mk_decrypted_inodes_lock);
+- if (refcount_dec_and_test(&mk->mk_refcount))
+- key_invalidate(key);
+- key_put(key);
++ fscrypt_put_master_key_activeref(mk);
+ }
+ memzero_explicit(ci, sizeof(*ci));
+ kmem_cache_free(fscrypt_info_cachep, ci);
+@@ -538,7 +527,7 @@ fscrypt_setup_encryption_info(struct ino
+ {
+ struct fscrypt_info *crypt_info;
+ struct fscrypt_mode *mode;
+- struct key *master_key = NULL;
++ struct fscrypt_master_key *mk = NULL;
+ int res;
+
+ res = fscrypt_initialize(inode->i_sb->s_cop->flags);
+@@ -561,8 +550,7 @@ fscrypt_setup_encryption_info(struct ino
+ WARN_ON(mode->ivsize > FSCRYPT_MAX_IV_SIZE);
+ crypt_info->ci_mode = mode;
+
+- res = setup_file_encryption_key(crypt_info, need_dirhash_key,
+- &master_key);
++ res = setup_file_encryption_key(crypt_info, need_dirhash_key, &mk);
+ if (res)
+ goto out;
+
+@@ -577,12 +565,9 @@ fscrypt_setup_encryption_info(struct ino
+ * We won the race and set ->i_crypt_info to our crypt_info.
+ * Now link it into the master key's inode list.
+ */
+- if (master_key) {
+- struct fscrypt_master_key *mk =
+- master_key->payload.data[0];
+-
+- refcount_inc(&mk->mk_refcount);
+- crypt_info->ci_master_key = key_get(master_key);
++ if (mk) {
++ crypt_info->ci_master_key = mk;
++ refcount_inc(&mk->mk_active_refs);
+ spin_lock(&mk->mk_decrypted_inodes_lock);
+ list_add(&crypt_info->ci_master_key_link,
+ &mk->mk_decrypted_inodes);
+@@ -592,9 +577,9 @@ fscrypt_setup_encryption_info(struct ino
+ }
+ res = 0;
+ out:
+- if (master_key) {
+- up_read(&master_key->sem);
+- key_put(master_key);
++ if (mk) {
++ up_read(&mk->mk_sem);
++ fscrypt_put_master_key(mk);
+ }
+ put_crypt_info(crypt_info);
+ return res;
+@@ -745,7 +730,6 @@ EXPORT_SYMBOL(fscrypt_free_inode);
+ int fscrypt_drop_inode(struct inode *inode)
+ {
+ const struct fscrypt_info *ci = fscrypt_get_info(inode);
+- const struct fscrypt_master_key *mk;
+
+ /*
+ * If ci is NULL, then the inode doesn't have an encryption key set up
+@@ -755,7 +739,6 @@ int fscrypt_drop_inode(struct inode *ino
+ */
+ if (!ci || !ci->ci_master_key)
+ return 0;
+- mk = ci->ci_master_key->payload.data[0];
+
+ /*
+ * With proper, non-racy use of FS_IOC_REMOVE_ENCRYPTION_KEY, all inodes
+@@ -774,6 +757,6 @@ int fscrypt_drop_inode(struct inode *ino
+ * then the thread removing the key will either evict the inode itself
+ * or will correctly detect that it wasn't evicted due to the race.
+ */
+- return !is_master_key_secret_present(&mk->mk_secret);
++ return !is_master_key_secret_present(&ci->ci_master_key->mk_secret);
+ }
+ EXPORT_SYMBOL_GPL(fscrypt_drop_inode);
+--- a/fs/crypto/policy.c
++++ b/fs/crypto/policy.c
+@@ -686,12 +686,8 @@ int fscrypt_set_context(struct inode *in
+ * delayed key setup that requires the inode number.
+ */
+ if (ci->ci_policy.version == FSCRYPT_POLICY_V2 &&
+- (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) {
+- const struct fscrypt_master_key *mk =
+- ci->ci_master_key->payload.data[0];
+-
+- fscrypt_hash_inode_number(ci, mk);
+- }
++ (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32))
++ fscrypt_hash_inode_number(ci, ci->ci_master_key);
+
+ return inode->i_sb->s_cop->set_context(inode, &ctx, ctxsize, fs_data);
+ }
+--- a/fs/super.c
++++ b/fs/super.c
+@@ -293,7 +293,6 @@ static void __put_super(struct super_blo
+ WARN_ON(s->s_inode_lru.node);
+ WARN_ON(!list_empty(&s->s_mounts));
+ security_sb_free(s);
+- fscrypt_sb_free(s);
+ put_user_ns(s->s_user_ns);
+ kfree(s->s_subtype);
+ call_rcu(&s->rcu, destroy_super_rcu);
+@@ -454,6 +453,7 @@ void generic_shutdown_super(struct super
+ evict_inodes(sb);
+ /* only nonzero refcount inodes can have marks */
+ fsnotify_sb_delete(sb);
++ fscrypt_sb_delete(sb);
+
+ if (sb->s_dio_done_wq) {
+ destroy_workqueue(sb->s_dio_done_wq);
+--- a/include/linux/fs.h
++++ b/include/linux/fs.h
+@@ -1437,7 +1437,7 @@ struct super_block {
+ const struct xattr_handler **s_xattr;
+ #ifdef CONFIG_FS_ENCRYPTION
+ const struct fscrypt_operations *s_cop;
+- struct key *s_master_keys; /* master crypto keys in use */
++ struct fscrypt_keyring *s_master_keys; /* master crypto keys in use */
+ #endif
+ #ifdef CONFIG_FS_VERITY
+ const struct fsverity_operations *s_vop;
+--- a/include/linux/fscrypt.h
++++ b/include/linux/fscrypt.h
+@@ -193,7 +193,7 @@ fscrypt_free_dummy_policy(struct fscrypt
+ }
+
+ /* keyring.c */
+-void fscrypt_sb_free(struct super_block *sb);
++void fscrypt_sb_delete(struct super_block *sb);
+ int fscrypt_ioctl_add_key(struct file *filp, void __user *arg);
+ int fscrypt_ioctl_remove_key(struct file *filp, void __user *arg);
+ int fscrypt_ioctl_remove_key_all_users(struct file *filp, void __user *arg);
+@@ -380,7 +380,7 @@ fscrypt_free_dummy_policy(struct fscrypt
+ }
+
+ /* keyring.c */
+-static inline void fscrypt_sb_free(struct super_block *sb)
++static inline void fscrypt_sb_delete(struct super_block *sb)
+ {
+ }
+
projects / thirdparty / kernel / stable-queue.git / commitdiff
