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Diffstat (limited to 'fs/crypto/keysetup.c')
-rw-r--r--fs/crypto/keysetup.c89
1 files changed, 37 insertions, 52 deletions
diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index fbc71abdabe3..f7407071a952 100644
--- 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"
@@ -155,10 +154,12 @@ int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key,
}
/* Destroy a crypto transform object and/or blk-crypto key. */
-void fscrypt_destroy_prepared_key(struct fscrypt_prepared_key *prep_key)
+void fscrypt_destroy_prepared_key(struct super_block *sb,
+ struct fscrypt_prepared_key *prep_key)
{
crypto_free_skcipher(prep_key->tfm);
- fscrypt_destroy_inline_crypt_key(prep_key);
+ fscrypt_destroy_inline_crypt_key(sb, prep_key);
+ memzero_explicit(prep_key, sizeof(*prep_key));
}
/* Given a per-file encryption key, set up the file's crypto transform object */
@@ -412,20 +413,18 @@ static bool fscrypt_valid_master_key_size(const struct fscrypt_master_key *mk,
/*
* 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);
@@ -436,11 +435,10 @@ static int setup_file_encryption_key(struct fscrypt_info *ci,
if (err)
return err;
- 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
@@ -450,9 +448,7 @@ static int setup_file_encryption_key(struct fscrypt_info *ci,
*/
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)) {
@@ -480,18 +476,18 @@ static int setup_file_encryption_key(struct fscrypt_info *ci,
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;
@@ -499,26 +495,21 @@ static void put_crypt_info(struct fscrypt_info *ci)
if (ci->ci_direct_key)
fscrypt_put_direct_key(ci->ci_direct_key);
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];
+ fscrypt_destroy_prepared_key(ci->ci_inode->i_sb,
+ &ci->ci_enc_key);
+ 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);
@@ -532,7 +523,7 @@ fscrypt_setup_encryption_info(struct inode *inode,
{
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);
@@ -555,8 +546,7 @@ fscrypt_setup_encryption_info(struct inode *inode,
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;
@@ -571,12 +561,9 @@ fscrypt_setup_encryption_info(struct inode *inode,
* 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);
@@ -586,9 +573,9 @@ fscrypt_setup_encryption_info(struct inode *inode,
}
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;
@@ -753,7 +740,6 @@ 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
@@ -763,7 +749,6 @@ int fscrypt_drop_inode(struct inode *inode)
*/
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
@@ -782,6 +767,6 @@ int fscrypt_drop_inode(struct inode *inode)
* 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);
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-14 18:54:25 +0300