diff options
Diffstat (limited to 'fs/crypto/inline_crypt.c')
| -rw-r--r-- | fs/crypto/inline_crypt.c | 152 |
1 files changed, 56 insertions, 96 deletions
diff --git a/fs/crypto/inline_crypt.c b/fs/crypto/inline_crypt.c index 40de69860dcf..47324062fee5 100644 --- a/fs/crypto/inline_crypt.c +++ b/fs/crypto/inline_crypt.c @@ -15,6 +15,7 @@ #include <linux/blk-crypto.h> #include <linux/blkdev.h> #include <linux/buffer_head.h> +#include <linux/export.h> #include <linux/sched/mm.h> #include <linux/slab.h> #include <linux/uio.h> @@ -31,7 +32,7 @@ static struct block_device **fscrypt_get_devices(struct super_block *sb, if (devs) return devs; } - devs = kmalloc(sizeof(*devs), GFP_KERNEL); + devs = kmalloc_obj(*devs); if (!devs) return ERR_PTR(-ENOMEM); devs[0] = sb->s_bdev; @@ -89,7 +90,8 @@ static void fscrypt_log_blk_crypto_impl(struct fscrypt_mode *mode, } /* Enable inline encryption for this file if supported. */ -int fscrypt_select_encryption_impl(struct fscrypt_inode_info *ci) +int fscrypt_select_encryption_impl(struct fscrypt_inode_info *ci, + bool is_hw_wrapped_key) { const struct inode *inode = ci->ci_inode; struct super_block *sb = inode->i_sb; @@ -130,6 +132,8 @@ int fscrypt_select_encryption_impl(struct fscrypt_inode_info *ci) crypto_cfg.crypto_mode = ci->ci_mode->blk_crypto_mode; crypto_cfg.data_unit_size = 1U << ci->ci_data_unit_bits; crypto_cfg.dun_bytes = fscrypt_get_dun_bytes(ci); + crypto_cfg.key_type = is_hw_wrapped_key ? + BLK_CRYPTO_KEY_TYPE_HW_WRAPPED : BLK_CRYPTO_KEY_TYPE_RAW; devs = fscrypt_get_devices(sb, &num_devs); if (IS_ERR(devs)) @@ -150,24 +154,27 @@ out_free_devs: } int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key, - const u8 *raw_key, + const u8 *key_bytes, size_t key_size, + bool is_hw_wrapped, const struct fscrypt_inode_info *ci) { const struct inode *inode = ci->ci_inode; struct super_block *sb = inode->i_sb; enum blk_crypto_mode_num crypto_mode = ci->ci_mode->blk_crypto_mode; + enum blk_crypto_key_type key_type = is_hw_wrapped ? + BLK_CRYPTO_KEY_TYPE_HW_WRAPPED : BLK_CRYPTO_KEY_TYPE_RAW; struct blk_crypto_key *blk_key; struct block_device **devs; unsigned int num_devs; unsigned int i; int err; - blk_key = kmalloc(sizeof(*blk_key), GFP_KERNEL); + blk_key = kmalloc_obj(*blk_key); if (!blk_key) return -ENOMEM; - err = blk_crypto_init_key(blk_key, raw_key, crypto_mode, - fscrypt_get_dun_bytes(ci), + err = blk_crypto_init_key(blk_key, key_bytes, key_size, key_type, + crypto_mode, fscrypt_get_dun_bytes(ci), 1U << ci->ci_data_unit_bits); if (err) { fscrypt_err(inode, "error %d initializing blk-crypto key", err); @@ -191,13 +198,7 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key, goto fail; } - /* - * Pairs with the smp_load_acquire() in fscrypt_is_key_prepared(). - * I.e., here we publish ->blk_key with a RELEASE barrier so that - * concurrent tasks can ACQUIRE it. Note that this concurrency is only - * possible for per-mode keys, not for per-file keys. - */ - smp_store_release(&prep_key->blk_key, blk_key); + prep_key->blk_key = blk_key; return 0; fail: @@ -226,21 +227,47 @@ void fscrypt_destroy_inline_crypt_key(struct super_block *sb, kfree_sensitive(blk_key); } +/* + * Ask the inline encryption hardware to derive the software secret from a + * hardware-wrapped key. Returns -EOPNOTSUPP if hardware-wrapped keys aren't + * supported on this filesystem or hardware. + */ +int fscrypt_derive_sw_secret(struct super_block *sb, + const u8 *wrapped_key, size_t wrapped_key_size, + u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE]) +{ + int err; + + /* The filesystem must be mounted with -o inlinecrypt. */ + if (!(sb->s_flags & SB_INLINECRYPT)) { + fscrypt_warn(NULL, + "%s: filesystem not mounted with inlinecrypt\n", + sb->s_id); + return -EOPNOTSUPP; + } + + err = blk_crypto_derive_sw_secret(sb->s_bdev, wrapped_key, + wrapped_key_size, sw_secret); + if (err == -EOPNOTSUPP) + fscrypt_warn(NULL, + "%s: block device doesn't support hardware-wrapped keys\n", + sb->s_id); + return err; +} + bool __fscrypt_inode_uses_inline_crypto(const struct inode *inode) { - return inode->i_crypt_info->ci_inlinecrypt; + return fscrypt_get_inode_info_raw(inode)->ci_inlinecrypt; } EXPORT_SYMBOL_GPL(__fscrypt_inode_uses_inline_crypto); static void fscrypt_generate_dun(const struct fscrypt_inode_info *ci, - u64 lblk_num, - u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE]) + loff_t pos, u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE]) { - u64 index = lblk_num << ci->ci_data_units_per_block_bits; union fscrypt_iv iv; int i; - fscrypt_generate_iv(&iv, index, ci); + fscrypt_generate_iv(&iv, pos >> ci->ci_data_unit_bits, ci); BUILD_BUG_ON(FSCRYPT_MAX_IV_SIZE > BLK_CRYPTO_MAX_IV_SIZE); memset(dun, 0, BLK_CRYPTO_MAX_IV_SIZE); @@ -252,7 +279,7 @@ static void fscrypt_generate_dun(const struct fscrypt_inode_info *ci, * fscrypt_set_bio_crypt_ctx() - prepare a file contents bio for inline crypto * @bio: a bio which will eventually be submitted to the file * @inode: the file's inode - * @first_lblk: the first file logical block number in the I/O + * @pos: the first file position (in bytes) in the I/O * @gfp_mask: memory allocation flags - these must be a waiting mask so that * bio_crypt_set_ctx can't fail. * @@ -265,71 +292,25 @@ static void fscrypt_generate_dun(const struct fscrypt_inode_info *ci, * The encryption context will be freed automatically when the bio is freed. */ void fscrypt_set_bio_crypt_ctx(struct bio *bio, const struct inode *inode, - u64 first_lblk, gfp_t gfp_mask) + loff_t pos, gfp_t gfp_mask) { const struct fscrypt_inode_info *ci; u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE]; if (!fscrypt_inode_uses_inline_crypto(inode)) return; - ci = inode->i_crypt_info; + ci = fscrypt_get_inode_info_raw(inode); - fscrypt_generate_dun(ci, first_lblk, dun); + fscrypt_generate_dun(ci, pos, dun); bio_crypt_set_ctx(bio, ci->ci_enc_key.blk_key, dun, gfp_mask); } EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx); -/* Extract the inode and logical block number from a buffer_head. */ -static bool bh_get_inode_and_lblk_num(const struct buffer_head *bh, - const struct inode **inode_ret, - u64 *lblk_num_ret) -{ - struct folio *folio = bh->b_folio; - const struct address_space *mapping; - const struct inode *inode; - - /* - * The ext4 journal (jbd2) can submit a buffer_head it directly created - * for a non-pagecache page. fscrypt doesn't care about these. - */ - mapping = folio_mapping(folio); - if (!mapping) - return false; - inode = mapping->host; - - *inode_ret = inode; - *lblk_num_ret = ((u64)folio->index << (PAGE_SHIFT - inode->i_blkbits)) + - (bh_offset(bh) >> inode->i_blkbits); - return true; -} - -/** - * fscrypt_set_bio_crypt_ctx_bh() - prepare a file contents bio for inline - * crypto - * @bio: a bio which will eventually be submitted to the file - * @first_bh: the first buffer_head for which I/O will be submitted - * @gfp_mask: memory allocation flags - * - * Same as fscrypt_set_bio_crypt_ctx(), except this takes a buffer_head instead - * of an inode and block number directly. - */ -void fscrypt_set_bio_crypt_ctx_bh(struct bio *bio, - const struct buffer_head *first_bh, - gfp_t gfp_mask) -{ - const struct inode *inode; - u64 first_lblk; - - if (bh_get_inode_and_lblk_num(first_bh, &inode, &first_lblk)) - fscrypt_set_bio_crypt_ctx(bio, inode, first_lblk, gfp_mask); -} -EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx_bh); - /** * fscrypt_mergeable_bio() - test whether data can be added to a bio * @bio: the bio being built up * @inode: the inode for the next part of the I/O - * @next_lblk: the next file logical block number in the I/O + * @pos: the next file position (in bytes) in the I/O * * When building a bio which may contain data which should undergo inline * encryption (or decryption) via fscrypt, filesystems should call this function @@ -347,53 +328,32 @@ EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx_bh); * Return: true iff the I/O is mergeable */ bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode, - u64 next_lblk) + loff_t pos) { const struct bio_crypt_ctx *bc = bio->bi_crypt_context; + const struct fscrypt_inode_info *ci; u64 next_dun[BLK_CRYPTO_DUN_ARRAY_SIZE]; if (!!bc != fscrypt_inode_uses_inline_crypto(inode)) return false; if (!bc) return true; + ci = fscrypt_get_inode_info_raw(inode); /* * Comparing the key pointers is good enough, as all I/O for each key * uses the same pointer. I.e., there's currently no need to support * merging requests where the keys are the same but the pointers differ. */ - if (bc->bc_key != inode->i_crypt_info->ci_enc_key.blk_key) + if (bc->bc_key != ci->ci_enc_key.blk_key) return false; - fscrypt_generate_dun(inode->i_crypt_info, next_lblk, next_dun); + fscrypt_generate_dun(ci, pos, next_dun); return bio_crypt_dun_is_contiguous(bc, bio->bi_iter.bi_size, next_dun); } EXPORT_SYMBOL_GPL(fscrypt_mergeable_bio); /** - * fscrypt_mergeable_bio_bh() - test whether data can be added to a bio - * @bio: the bio being built up - * @next_bh: the next buffer_head for which I/O will be submitted - * - * Same as fscrypt_mergeable_bio(), except this takes a buffer_head instead of - * an inode and block number directly. - * - * Return: true iff the I/O is mergeable - */ -bool fscrypt_mergeable_bio_bh(struct bio *bio, - const struct buffer_head *next_bh) -{ - const struct inode *inode; - u64 next_lblk; - - if (!bh_get_inode_and_lblk_num(next_bh, &inode, &next_lblk)) - return !bio->bi_crypt_context; - - return fscrypt_mergeable_bio(bio, inode, next_lblk); -} -EXPORT_SYMBOL_GPL(fscrypt_mergeable_bio_bh); - -/** * fscrypt_dio_supported() - check whether DIO (direct I/O) is supported on an * inode, as far as encryption is concerned * @inode: the inode in question @@ -467,7 +427,7 @@ u64 fscrypt_limit_io_blocks(const struct inode *inode, u64 lblk, u64 nr_blocks) if (nr_blocks <= 1) return nr_blocks; - ci = inode->i_crypt_info; + ci = fscrypt_get_inode_info_raw(inode); if (!(fscrypt_policy_flags(&ci->ci_policy) & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) return nr_blocks; |