diff options
-rw-r--r-- | fs/ext4/crypto.c | 64 | ||||
-rw-r--r-- | fs/ext4/crypto_fname.c | 48 | ||||
-rw-r--r-- | fs/ext4/crypto_key.c | 108 | ||||
-rw-r--r-- | fs/ext4/dir.c | 3 | ||||
-rw-r--r-- | fs/ext4/ext4.h | 5 | ||||
-rw-r--r-- | fs/ext4/ext4_crypto.h | 3 | ||||
-rw-r--r-- | fs/ext4/namei.c | 17 | ||||
-rw-r--r-- | fs/ext4/super.c | 2 | ||||
-rw-r--r-- | fs/ext4/symlink.c | 2 |
9 files changed, 96 insertions, 156 deletions
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 28a0e4bd91b0..c3a9b08309db 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 e63dd294d7aa..29a2dc9a6f82 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 858d7d67a4e1..442d24e8efc0 100644 --- a/fs/ext4/crypto_key.c +++ b/fs/ext4/crypto_key.c @@ -84,20 +84,32 @@ out: 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 28cb94fbb1c9..e11e6ae26baa 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 23e33fb3202e..7435ff2c3efb 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 c5258f242215..34e0d2455881 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 9bed99fdd81a..6ab50f80964f 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 b0bd1c1061b3..56bfc2f25d90 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 32870881188e..68e915aac0fe 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); |