diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index 28a0e4bd91b0d00ad188ad40078cebaa64098c16..c3a9b08309db193cbcbbc44cd5962a57c3f134b8 100644
--- a/fs/ext4/crypto.c
+++ b/fs/ext4/crypto.c
@@ -80,8 +80,6 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx)
ctx->w.bounce_page = NULL;
ctx->w.control_page = NULL;
if (ctx->flags & EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL) {
- if (ctx->tfm)
- crypto_free_tfm(ctx->tfm);
kmem_cache_free(ext4_crypto_ctx_cachep, ctx);
} else {
spin_lock_irqsave(&ext4_crypto_ctx_lock, flags);
@@ -136,36 +134,6 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
}
ctx->flags &= ~EXT4_WRITE_PATH_FL;
- /* Allocate a new Crypto API context if we don't already have
- * one or if it isn't the right mode. */
- if (ctx->tfm && (ctx->mode != ci->ci_data_mode)) {
- crypto_free_tfm(ctx->tfm);
- ctx->tfm = NULL;
- ctx->mode = EXT4_ENCRYPTION_MODE_INVALID;
- }
- if (!ctx->tfm) {
- switch (ci->ci_data_mode) {
- case EXT4_ENCRYPTION_MODE_AES_256_XTS:
- ctx->tfm = crypto_ablkcipher_tfm(
- crypto_alloc_ablkcipher("xts(aes)", 0, 0));
- break;
- case EXT4_ENCRYPTION_MODE_AES_256_GCM:
- /* TODO(mhalcrow): AEAD w/ gcm(aes);
- * crypto_aead_setauthsize() */
- ctx->tfm = ERR_PTR(-ENOTSUPP);
- break;
- default:
- BUG();
- }
- if (IS_ERR_OR_NULL(ctx->tfm)) {
- res = PTR_ERR(ctx->tfm);
- ctx->tfm = NULL;
- goto out;
- }
- ctx->mode = ci->ci_data_mode;
- }
- BUG_ON(ci->ci_size != ext4_encryption_key_size(ci->ci_data_mode));
-
out:
if (res) {
if (!IS_ERR_OR_NULL(ctx))
@@ -185,11 +153,8 @@ void ext4_exit_crypto(void)
{
struct ext4_crypto_ctx *pos, *n;
- list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list) {
- if (pos->tfm)
- crypto_free_tfm(pos->tfm);
+ list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list)
kmem_cache_free(ext4_crypto_ctx_cachep, pos);
- }
INIT_LIST_HEAD(&ext4_free_crypto_ctxs);
if (ext4_bounce_page_pool)
mempool_destroy(ext4_bounce_page_pool);
@@ -303,32 +268,11 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
struct ablkcipher_request *req = NULL;
DECLARE_EXT4_COMPLETION_RESULT(ecr);
struct scatterlist dst, src;
- struct ext4_inode_info *ei = EXT4_I(inode);
- struct crypto_ablkcipher *atfm = __crypto_ablkcipher_cast(ctx->tfm);
+ struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+ struct crypto_ablkcipher *tfm = ci->ci_ctfm;
int res = 0;
- BUG_ON(!ctx->tfm);
- BUG_ON(ctx->mode != ei->i_crypt_info->ci_data_mode);
-
- if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) {
- printk_ratelimited(KERN_ERR
- "%s: unsupported crypto algorithm: %d\n",
- __func__, ctx->mode);
- return -ENOTSUPP;
- }
-
- crypto_ablkcipher_clear_flags(atfm, ~0);
- crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_REQ_WEAK_KEY);
-
- res = crypto_ablkcipher_setkey(atfm, ei->i_crypt_info->ci_raw,
- ei->i_crypt_info->ci_size);
- if (res) {
- printk_ratelimited(KERN_ERR
- "%s: crypto_ablkcipher_setkey() failed\n",
- __func__);
- return res;
- }
- req = ablkcipher_request_alloc(atfm, GFP_NOFS);
+ req = ablkcipher_request_alloc(tfm, GFP_NOFS);
if (!req) {
printk_ratelimited(KERN_ERR
"%s: crypto_request_alloc() failed\n",
diff --git a/fs/ext4/crypto_fname.c b/fs/ext4/crypto_fname.c
index e63dd294d7aad53f5c28be04e6a4105a3ec86dd8..29a2dc9a6f824f3dbebe6cbc076df0db6b5d51e5 100644
--- a/fs/ext4/crypto_fname.c
+++ b/fs/ext4/crypto_fname.c
@@ -252,52 +252,6 @@ static int digest_decode(const char *src, int len, char *dst)
return cp - dst;
}
-int ext4_setup_fname_crypto(struct inode *inode)
-{
- struct ext4_inode_info *ei = EXT4_I(inode);
- struct ext4_crypt_info *ci = ei->i_crypt_info;
- struct crypto_ablkcipher *ctfm;
- int res;
-
- /* Check if the crypto policy is set on the inode */
- res = ext4_encrypted_inode(inode);
- if (res == 0)
- return 0;
-
- res = ext4_get_encryption_info(inode);
- if (res < 0)
- return res;
- ci = ei->i_crypt_info;
-
- if (!ci || ci->ci_ctfm)
- return 0;
-
- if (ci->ci_filename_mode != EXT4_ENCRYPTION_MODE_AES_256_CTS) {
- printk_once(KERN_WARNING "ext4: unsupported key mode %d\n",
- ci->ci_filename_mode);
- return -ENOKEY;
- }
-
- ctfm = crypto_alloc_ablkcipher("cts(cbc(aes))", 0, 0);
- if (!ctfm || IS_ERR(ctfm)) {
- res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
- printk(KERN_DEBUG "%s: error (%d) allocating crypto tfm\n",
- __func__, res);
- return res;
- }
- crypto_ablkcipher_clear_flags(ctfm, ~0);
- crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctfm),
- CRYPTO_TFM_REQ_WEAK_KEY);
-
- res = crypto_ablkcipher_setkey(ctfm, ci->ci_raw, ci->ci_size);
- if (res) {
- crypto_free_ablkcipher(ctfm);
- return -EIO;
- }
- ci->ci_ctfm = ctfm;
- return 0;
-}
-
/**
* ext4_fname_crypto_round_up() -
*
@@ -449,7 +403,7 @@ int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
fname->disk_name.len = iname->len;
goto out;
}
- ret = ext4_setup_fname_crypto(dir);
+ ret = ext4_get_encryption_info(dir);
if (ret)
return ret;
ci = EXT4_I(dir)->i_crypt_info;
diff --git a/fs/ext4/crypto_key.c b/fs/ext4/crypto_key.c
index 858d7d67a4e19c47ed877e633873f093f86db07a..442d24e8efc0cec6281a745384b3139433128ac4 100644
--- a/fs/ext4/crypto_key.c
+++ b/fs/ext4/crypto_key.c
@@ -84,20 +84,32 @@ static int ext4_derive_key_aes(char deriving_key[EXT4_AES_128_ECB_KEY_SIZE],
return res;
}
-void ext4_free_encryption_info(struct inode *inode)
+void ext4_free_crypt_info(struct ext4_crypt_info *ci)
{
- struct ext4_inode_info *ei = EXT4_I(inode);
- struct ext4_crypt_info *ci = ei->i_crypt_info;
-
if (!ci)
return;
if (ci->ci_keyring_key)
key_put(ci->ci_keyring_key);
crypto_free_ablkcipher(ci->ci_ctfm);
- memzero_explicit(&ci->ci_raw, sizeof(ci->ci_raw));
kmem_cache_free(ext4_crypt_info_cachep, ci);
- ei->i_crypt_info = NULL;
+}
+
+void ext4_free_encryption_info(struct inode *inode,
+ struct ext4_crypt_info *ci)
+{
+ struct ext4_inode_info *ei = EXT4_I(inode);
+ struct ext4_crypt_info *prev;
+
+ if (ci == NULL)
+ ci = ACCESS_ONCE(ei->i_crypt_info);
+ if (ci == NULL)
+ return;
+ prev = cmpxchg(&ei->i_crypt_info, ci, NULL);
+ if (prev != ci)
+ return;
+
+ ext4_free_crypt_info(ci);
}
int _ext4_get_encryption_info(struct inode *inode)
@@ -111,6 +123,10 @@ int _ext4_get_encryption_info(struct inode *inode)
struct ext4_encryption_context ctx;
struct user_key_payload *ukp;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ struct crypto_ablkcipher *ctfm;
+ const char *cipher_str;
+ char raw_key[EXT4_MAX_KEY_SIZE];
+ char mode;
int res;
if (!ext4_read_workqueue) {
@@ -119,11 +135,14 @@ int _ext4_get_encryption_info(struct inode *inode)
return res;
}
- if (ei->i_crypt_info) {
- if (!ei->i_crypt_info->ci_keyring_key ||
- key_validate(ei->i_crypt_info->ci_keyring_key) == 0)
+retry:
+ crypt_info = ACCESS_ONCE(ei->i_crypt_info);
+ if (crypt_info) {
+ if (!crypt_info->ci_keyring_key ||
+ key_validate(crypt_info->ci_keyring_key) == 0)
return 0;
- ext4_free_encryption_info(inode);
+ ext4_free_encryption_info(inode, crypt_info);
+ goto retry;
}
res = ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
@@ -144,26 +163,37 @@ int _ext4_get_encryption_info(struct inode *inode)
if (!crypt_info)
return -ENOMEM;
- ei->i_crypt_policy_flags = ctx.flags;
crypt_info->ci_flags = ctx.flags;
crypt_info->ci_data_mode = ctx.contents_encryption_mode;
crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
crypt_info->ci_ctfm = NULL;
+ crypt_info->ci_keyring_key = NULL;
memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
sizeof(crypt_info->ci_master_key));
if (S_ISREG(inode->i_mode))
- crypt_info->ci_size =
- ext4_encryption_key_size(crypt_info->ci_data_mode);
+ mode = crypt_info->ci_data_mode;
else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
- crypt_info->ci_size =
- ext4_encryption_key_size(crypt_info->ci_filename_mode);
+ mode = crypt_info->ci_filename_mode;
else
BUG();
- BUG_ON(!crypt_info->ci_size);
- if (DUMMY_ENCRYPTION_ENABLED(sbi)) {
- memset(crypt_info->ci_raw, 0x42, EXT4_AES_256_XTS_KEY_SIZE);
+ switch (mode) {
+ case EXT4_ENCRYPTION_MODE_AES_256_XTS:
+ cipher_str = "xts(aes)";
+ break;
+ case EXT4_ENCRYPTION_MODE_AES_256_CTS:
+ cipher_str = "cts(cbc(aes))";
+ break;
+ default:
+ printk_once(KERN_WARNING
+ "ext4: unsupported key mode %d (ino %u)\n",
+ mode, (unsigned) inode->i_ino);
+ res = -ENOKEY;
goto out;
}
+ if (DUMMY_ENCRYPTION_ENABLED(sbi)) {
+ memset(raw_key, 0x42, EXT4_AES_256_XTS_KEY_SIZE);
+ goto got_key;
+ }
memcpy(full_key_descriptor, EXT4_KEY_DESC_PREFIX,
EXT4_KEY_DESC_PREFIX_SIZE);
sprintf(full_key_descriptor + EXT4_KEY_DESC_PREFIX_SIZE,
@@ -177,6 +207,7 @@ int _ext4_get_encryption_info(struct inode *inode)
keyring_key = NULL;
goto out;
}
+ crypt_info->ci_keyring_key = keyring_key;
BUG_ON(keyring_key->type != &key_type_logon);
ukp = ((struct user_key_payload *)keyring_key->payload.data);
if (ukp->datalen != sizeof(struct ext4_encryption_key)) {
@@ -188,19 +219,36 @@ int _ext4_get_encryption_info(struct inode *inode)
EXT4_KEY_DERIVATION_NONCE_SIZE);
BUG_ON(master_key->size != EXT4_AES_256_XTS_KEY_SIZE);
res = ext4_derive_key_aes(ctx.nonce, master_key->raw,
- crypt_info->ci_raw);
-out:
- if (res < 0) {
- if (res == -ENOKEY)
- res = 0;
- kmem_cache_free(ext4_crypt_info_cachep, crypt_info);
- } else {
- ei->i_crypt_info = crypt_info;
- crypt_info->ci_keyring_key = keyring_key;
- keyring_key = NULL;
+ raw_key);
+got_key:
+ ctfm = crypto_alloc_ablkcipher(cipher_str, 0, 0);
+ if (!ctfm || IS_ERR(ctfm)) {
+ res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
+ printk(KERN_DEBUG
+ "%s: error %d (inode %u) allocating crypto tfm\n",
+ __func__, res, (unsigned) inode->i_ino);
+ goto out;
+ }
+ crypt_info->ci_ctfm = ctfm;
+ crypto_ablkcipher_clear_flags(ctfm, ~0);
+ crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctfm),
+ CRYPTO_TFM_REQ_WEAK_KEY);
+ res = crypto_ablkcipher_setkey(ctfm, raw_key,
+ ext4_encryption_key_size(mode));
+ if (res)
+ goto out;
+ memzero_explicit(raw_key, sizeof(raw_key));
+ if (cmpxchg(&ei->i_crypt_info, NULL, crypt_info) != NULL) {
+ ext4_free_crypt_info(crypt_info);
+ goto retry;
}
- if (keyring_key)
- key_put(keyring_key);
+ return 0;
+
+out:
+ if (res == -ENOKEY)
+ res = 0;
+ ext4_free_crypt_info(crypt_info);
+ memzero_explicit(raw_key, sizeof(raw_key));
return res;
}
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 28cb94fbb1c9df4df393b7628a15a8e5e14b8701..e11e6ae26baa6546a37a5a4e75b373df37349afb 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -133,9 +133,6 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
return err;
}
- err = ext4_setup_fname_crypto(inode);
- if (err)
- return err;
if (ext4_encrypted_inode(inode)) {
err = ext4_fname_crypto_alloc_buffer(inode, EXT4_NAME_LEN,
&fname_crypto_str);
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 23e33fb3202ede13ba0703bc4149c0077b1d2705..7435ff2c3efb9f79ccd597131bc1599237919ab5 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -911,7 +911,6 @@ struct ext4_inode_info {
/* on-disk additional length */
__u16 i_extra_isize;
- char i_crypt_policy_flags;
/* Indicate the inline data space. */
u16 i_inline_off;
@@ -2105,7 +2104,6 @@ int ext4_fname_usr_to_disk(struct inode *inode,
const struct qstr *iname,
struct ext4_str *oname);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
-int ext4_setup_fname_crypto(struct inode *inode);
void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str);
int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
int lookup, struct ext4_filename *fname);
@@ -2131,7 +2129,8 @@ static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
/* crypto_key.c */
-void ext4_free_encryption_info(struct inode *inode);
+void ext4_free_crypt_info(struct ext4_crypt_info *ci);
+void ext4_free_encryption_info(struct inode *inode, struct ext4_crypt_info *ci);
int _ext4_get_encryption_info(struct inode *inode);
#ifdef CONFIG_EXT4_FS_ENCRYPTION
diff --git a/fs/ext4/ext4_crypto.h b/fs/ext4/ext4_crypto.h
index c5258f24221549a2d7ef8e48cbe473c99027c986..34e0d2455881022423314108143002a129028b4b 100644
--- a/fs/ext4/ext4_crypto.h
+++ b/fs/ext4/ext4_crypto.h
@@ -74,13 +74,11 @@ struct ext4_encryption_key {
} __attribute__((__packed__));
struct ext4_crypt_info {
- unsigned char ci_size;
char ci_data_mode;
char ci_filename_mode;
char ci_flags;
struct crypto_ablkcipher *ci_ctfm;
struct key *ci_keyring_key;
- char ci_raw[EXT4_MAX_KEY_SIZE];
char ci_master_key[EXT4_KEY_DESCRIPTOR_SIZE];
};
@@ -89,7 +87,6 @@ struct ext4_crypt_info {
#define EXT4_WRITE_PATH_FL 0x00000004
struct ext4_crypto_ctx {
- struct crypto_tfm *tfm; /* Crypto API context */
union {
struct {
struct page *bounce_page; /* Ciphertext page */
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 9bed99fdd81a0d4afe17863ee026bb12d70b4f9e..6ab50f80964fda882600271d84024f47efdfeb2b 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -607,11 +607,12 @@ static struct stats dx_show_leaf(struct inode *dir,
char *name;
struct ext4_str fname_crypto_str
= {.name = NULL, .len = 0};
- int res;
+ int res = 0;
name = de->name;
len = de->name_len;
- res = ext4_setup_fname_crypto(dir);
+ if (ext4_encrypted_inode(inode))
+ res = ext4_get_encryption_info(dir);
if (res) {
printk(KERN_WARNING "Error setting up"
" fname crypto: %d\n", res);
@@ -953,12 +954,12 @@ static int htree_dirblock_to_tree(struct file *dir_file,
EXT4_DIR_REC_LEN(0));
#ifdef CONFIG_EXT4_FS_ENCRYPTION
/* Check if the directory is encrypted */
- err = ext4_setup_fname_crypto(dir);
- if (err) {
- brelse(bh);
- return err;
- }
if (ext4_encrypted_inode(dir)) {
+ err = ext4_get_encryption_info(dir);
+ if (err < 0) {
+ brelse(bh);
+ return err;
+ }
err = ext4_fname_crypto_alloc_buffer(dir, EXT4_NAME_LEN,
&fname_crypto_str);
if (err < 0) {
@@ -3108,7 +3109,7 @@ static int ext4_symlink(struct inode *dir,
err = ext4_inherit_context(dir, inode);
if (err)
goto err_drop_inode;
- err = ext4_setup_fname_crypto(inode);
+ err = ext4_get_encryption_info(inode);
if (err)
goto err_drop_inode;
istr.name = (const unsigned char *) symname;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b0bd1c1061b3dd991037da1c0a52fa06564990fa..56bfc2f25d90edb0cff900e1895669b4b5e5fd11 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -959,7 +959,7 @@ void ext4_clear_inode(struct inode *inode)
}
#ifdef CONFIG_EXT4_FS_ENCRYPTION
if (EXT4_I(inode)->i_crypt_info)
- ext4_free_encryption_info(inode);
+ ext4_free_encryption_info(inode, EXT4_I(inode)->i_crypt_info);
#endif
}
diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c
index 32870881188e63b1b8faa83af99ad34f0a1ec9a2..68e915aac0fe73dc33052675b5cb2d29072ac8df 100644
--- a/fs/ext4/symlink.c
+++ b/fs/ext4/symlink.c
@@ -37,7 +37,7 @@ static void *ext4_follow_link(struct dentry *dentry, struct nameidata *nd)
if (!ext4_encrypted_inode(inode))
return page_follow_link_light(dentry, nd);
- res = ext4_setup_fname_crypto(inode);
+ res = ext4_get_encryption_info(inode);
if (res)
return ERR_PTR(res);