| Message ID | 20230516052306.99600-1-ebiggers@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | [v2] fsverity: use shash API instead of ahash API | expand |
I'm not really an expert on fsverify, but the rationale of not using
clumsy external crypto offloads from the file system makes sense, and
the code looks much nicer now:
Reviewed-by: Christoph Hellwig <hch@lst.de>
On Tue, 16 May 2023 at 07:24, Eric Biggers <ebiggers@kernel.org> wrote: > > From: Eric Biggers <ebiggers@google.com> > > The "ahash" API, like the other scatterlist-based crypto APIs such as > "skcipher", comes with some well-known limitations. First, it can't > easily be used with vmalloc addresses. Second, the request struct can't > be allocated on the stack. This adds complexity and a possible failure > point that needs to be worked around, e.g. using a mempool. > > The only benefit of ahash over "shash" is that ahash is needed to access > traditional memory-to-memory crypto accelerators, i.e. drivers/crypto/. > However, this style of crypto acceleration has largely fallen out of > favor and been superseded by CPU-based acceleration or inline crypto > engines. Also, ahash needs to be used asynchronously to take full > advantage of such hardware, but fs/verity/ has never done this. > > On all systems that aren't actually using one of these ahash-only crypto > accelerators, ahash just adds unnecessary overhead as it sits between > the user and the underlying shash algorithms. > > Also, XFS is planned to cache fsverity Merkle tree blocks in the > existing XFS buffer cache. As a result, it will be possible for a > single Merkle tree block to be split across discontiguous pages > (https://lore.kernel.org/r/20230405233753.GU3223426@dread.disaster.area). > This data will need to be hashed. It is easiest to work with a vmapped > address in this case. However, ahash is incompatible with this. > > Therefore, let's convert fs/verity/ from ahash to shash. This > simplifies the code, and it should also slightly improve performance for > everyone who wasn't actually using one of these ahash-only crypto > accelerators, i.e. almost everyone (or maybe even everyone)! > > Signed-off-by: Eric Biggers <ebiggers@google.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> > --- > > v2: rebased onto v6.4-rc2. > > fs/verity/enable.c | 19 ++--- > fs/verity/fsverity_private.h | 13 +--- > fs/verity/hash_algs.c | 131 ++++++----------------------------- > fs/verity/verify.c | 108 +++++++++++------------------ > 4 files changed, 71 insertions(+), 200 deletions(-) > > diff --git a/fs/verity/enable.c b/fs/verity/enable.c > index fc4c50e5219dc..bd86b25ac084b 100644 > --- a/fs/verity/enable.c > +++ b/fs/verity/enable.c > @@ -7,6 +7,7 @@ > > #include "fsverity_private.h" > > +#include <crypto/hash.h> > #include <linux/mount.h> > #include <linux/sched/signal.h> > #include <linux/uaccess.h> > @@ -20,7 +21,7 @@ struct block_buffer { > /* Hash a block, writing the result to the next level's pending block buffer. */ > static int hash_one_block(struct inode *inode, > const struct merkle_tree_params *params, > - struct ahash_request *req, struct block_buffer *cur) > + struct block_buffer *cur) > { > struct block_buffer *next = cur + 1; > int err; > @@ -36,8 +37,7 @@ static int hash_one_block(struct inode *inode, > /* Zero-pad the block if it's shorter than the block size. */ > memset(&cur->data[cur->filled], 0, params->block_size - cur->filled); > > - err = fsverity_hash_block(params, inode, req, virt_to_page(cur->data), > - offset_in_page(cur->data), > + err = fsverity_hash_block(params, inode, cur->data, > &next->data[next->filled]); > if (err) > return err; > @@ -76,7 +76,6 @@ static int build_merkle_tree(struct file *filp, > struct inode *inode = file_inode(filp); > const u64 data_size = inode->i_size; > const int num_levels = params->num_levels; > - struct ahash_request *req; > struct block_buffer _buffers[1 + FS_VERITY_MAX_LEVELS + 1] = {}; > struct block_buffer *buffers = &_buffers[1]; > unsigned long level_offset[FS_VERITY_MAX_LEVELS]; > @@ -90,9 +89,6 @@ static int build_merkle_tree(struct file *filp, > return 0; > } > > - /* This allocation never fails, since it's mempool-backed. */ > - req = fsverity_alloc_hash_request(params->hash_alg, GFP_KERNEL); > - > /* > * Allocate the block buffers. Buffer "-1" is for data blocks. > * Buffers 0 <= level < num_levels are for the actual tree levels. > @@ -130,7 +126,7 @@ static int build_merkle_tree(struct file *filp, > fsverity_err(inode, "Short read of file data"); > goto out; > } > - err = hash_one_block(inode, params, req, &buffers[-1]); > + err = hash_one_block(inode, params, &buffers[-1]); > if (err) > goto out; > for (level = 0; level < num_levels; level++) { > @@ -141,8 +137,7 @@ static int build_merkle_tree(struct file *filp, > } > /* Next block at @level is full */ > > - err = hash_one_block(inode, params, req, > - &buffers[level]); > + err = hash_one_block(inode, params, &buffers[level]); > if (err) > goto out; > err = write_merkle_tree_block(inode, > @@ -162,8 +157,7 @@ static int build_merkle_tree(struct file *filp, > /* Finish all nonempty pending tree blocks. */ > for (level = 0; level < num_levels; level++) { > if (buffers[level].filled != 0) { > - err = hash_one_block(inode, params, req, > - &buffers[level]); > + err = hash_one_block(inode, params, &buffers[level]); > if (err) > goto out; > err = write_merkle_tree_block(inode, > @@ -183,7 +177,6 @@ static int build_merkle_tree(struct file *filp, > out: > for (level = -1; level < num_levels; level++) > kfree(buffers[level].data); > - fsverity_free_hash_request(params->hash_alg, req); > return err; > } > > diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h > index d34dcc033d723..8527beca2a454 100644 > --- a/fs/verity/fsverity_private.h > +++ b/fs/verity/fsverity_private.h > @@ -11,9 +11,6 @@ > #define pr_fmt(fmt) "fs-verity: " fmt > > #include <linux/fsverity.h> > -#include <linux/mempool.h> > - > -struct ahash_request; > > /* > * Implementation limit: maximum depth of the Merkle tree. For now 8 is plenty; > @@ -23,11 +20,10 @@ struct ahash_request; > > /* A hash algorithm supported by fs-verity */ > struct fsverity_hash_alg { > - struct crypto_ahash *tfm; /* hash tfm, allocated on demand */ > + struct crypto_shash *tfm; /* hash tfm, allocated on demand */ > const char *name; /* crypto API name, e.g. sha256 */ > unsigned int digest_size; /* digest size in bytes, e.g. 32 for SHA-256 */ > unsigned int block_size; /* block size in bytes, e.g. 64 for SHA-256 */ > - mempool_t req_pool; /* mempool with a preallocated hash request */ > /* > * The HASH_ALGO_* constant for this algorithm. This is different from > * FS_VERITY_HASH_ALG_*, which uses a different numbering scheme. > @@ -85,15 +81,10 @@ extern struct fsverity_hash_alg fsverity_hash_algs[]; > > struct fsverity_hash_alg *fsverity_get_hash_alg(const struct inode *inode, > unsigned int num); > -struct ahash_request *fsverity_alloc_hash_request(struct fsverity_hash_alg *alg, > - gfp_t gfp_flags); > -void fsverity_free_hash_request(struct fsverity_hash_alg *alg, > - struct ahash_request *req); > const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg, > const u8 *salt, size_t salt_size); > int fsverity_hash_block(const struct merkle_tree_params *params, > - const struct inode *inode, struct ahash_request *req, > - struct page *page, unsigned int offset, u8 *out); > + const struct inode *inode, const void *data, u8 *out); > int fsverity_hash_buffer(struct fsverity_hash_alg *alg, > const void *data, size_t size, u8 *out); > void __init fsverity_check_hash_algs(void); > diff --git a/fs/verity/hash_algs.c b/fs/verity/hash_algs.c > index ea00dbedf756b..e7e982412e23a 100644 > --- a/fs/verity/hash_algs.c > +++ b/fs/verity/hash_algs.c > @@ -8,7 +8,6 @@ > #include "fsverity_private.h" > > #include <crypto/hash.h> > -#include <linux/scatterlist.h> > > /* The hash algorithms supported by fs-verity */ > struct fsverity_hash_alg fsverity_hash_algs[] = { > @@ -44,7 +43,7 @@ struct fsverity_hash_alg *fsverity_get_hash_alg(const struct inode *inode, > unsigned int num) > { > struct fsverity_hash_alg *alg; > - struct crypto_ahash *tfm; > + struct crypto_shash *tfm; > int err; > > if (num >= ARRAY_SIZE(fsverity_hash_algs) || > @@ -63,11 +62,7 @@ struct fsverity_hash_alg *fsverity_get_hash_alg(const struct inode *inode, > if (alg->tfm != NULL) > goto out_unlock; > > - /* > - * Using the shash API would make things a bit simpler, but the ahash > - * API is preferable as it allows the use of crypto accelerators. > - */ > - tfm = crypto_alloc_ahash(alg->name, 0, 0); > + tfm = crypto_alloc_shash(alg->name, 0, 0); > if (IS_ERR(tfm)) { > if (PTR_ERR(tfm) == -ENOENT) { > fsverity_warn(inode, > @@ -84,68 +79,26 @@ struct fsverity_hash_alg *fsverity_get_hash_alg(const struct inode *inode, > } > > err = -EINVAL; > - if (WARN_ON_ONCE(alg->digest_size != crypto_ahash_digestsize(tfm))) > + if (WARN_ON_ONCE(alg->digest_size != crypto_shash_digestsize(tfm))) > goto err_free_tfm; > - if (WARN_ON_ONCE(alg->block_size != crypto_ahash_blocksize(tfm))) > - goto err_free_tfm; > - > - err = mempool_init_kmalloc_pool(&alg->req_pool, 1, > - sizeof(struct ahash_request) + > - crypto_ahash_reqsize(tfm)); > - if (err) > + if (WARN_ON_ONCE(alg->block_size != crypto_shash_blocksize(tfm))) > goto err_free_tfm; > > pr_info("%s using implementation \"%s\"\n", > - alg->name, crypto_ahash_driver_name(tfm)); > + alg->name, crypto_shash_driver_name(tfm)); > > /* pairs with smp_load_acquire() above */ > smp_store_release(&alg->tfm, tfm); > goto out_unlock; > > err_free_tfm: > - crypto_free_ahash(tfm); > + crypto_free_shash(tfm); > alg = ERR_PTR(err); > out_unlock: > mutex_unlock(&fsverity_hash_alg_init_mutex); > return alg; > } > > -/** > - * fsverity_alloc_hash_request() - allocate a hash request object > - * @alg: the hash algorithm for which to allocate the request > - * @gfp_flags: memory allocation flags > - * > - * This is mempool-backed, so this never fails if __GFP_DIRECT_RECLAIM is set in > - * @gfp_flags. However, in that case this might need to wait for all > - * previously-allocated requests to be freed. So to avoid deadlocks, callers > - * must never need multiple requests at a time to make forward progress. > - * > - * Return: the request object on success; NULL on failure (but see above) > - */ > -struct ahash_request *fsverity_alloc_hash_request(struct fsverity_hash_alg *alg, > - gfp_t gfp_flags) > -{ > - struct ahash_request *req = mempool_alloc(&alg->req_pool, gfp_flags); > - > - if (req) > - ahash_request_set_tfm(req, alg->tfm); > - return req; > -} > - > -/** > - * fsverity_free_hash_request() - free a hash request object > - * @alg: the hash algorithm > - * @req: the hash request object to free > - */ > -void fsverity_free_hash_request(struct fsverity_hash_alg *alg, > - struct ahash_request *req) > -{ > - if (req) { > - ahash_request_zero(req); > - mempool_free(req, &alg->req_pool); > - } > -} > - > /** > * fsverity_prepare_hash_state() - precompute the initial hash state > * @alg: hash algorithm > @@ -159,23 +112,20 @@ const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg, > const u8 *salt, size_t salt_size) > { > u8 *hashstate = NULL; > - struct ahash_request *req = NULL; > + SHASH_DESC_ON_STACK(desc, alg->tfm); > u8 *padded_salt = NULL; > size_t padded_salt_size; > - struct scatterlist sg; > - DECLARE_CRYPTO_WAIT(wait); > int err; > > + desc->tfm = alg->tfm; > + > if (salt_size == 0) > return NULL; > > - hashstate = kmalloc(crypto_ahash_statesize(alg->tfm), GFP_KERNEL); > + hashstate = kmalloc(crypto_shash_statesize(alg->tfm), GFP_KERNEL); > if (!hashstate) > return ERR_PTR(-ENOMEM); > > - /* This allocation never fails, since it's mempool-backed. */ > - req = fsverity_alloc_hash_request(alg, GFP_KERNEL); > - > /* > * Zero-pad the salt to the next multiple of the input size of the hash > * algorithm's compression function, e.g. 64 bytes for SHA-256 or 128 > @@ -190,26 +140,18 @@ const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg, > goto err_free; > } > memcpy(padded_salt, salt, salt_size); > - > - sg_init_one(&sg, padded_salt, padded_salt_size); > - ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | > - CRYPTO_TFM_REQ_MAY_BACKLOG, > - crypto_req_done, &wait); > - ahash_request_set_crypt(req, &sg, NULL, padded_salt_size); > - > - err = crypto_wait_req(crypto_ahash_init(req), &wait); > + err = crypto_shash_init(desc); > if (err) > goto err_free; > > - err = crypto_wait_req(crypto_ahash_update(req), &wait); > + err = crypto_shash_update(desc, padded_salt, padded_salt_size); > if (err) > goto err_free; > > - err = crypto_ahash_export(req, hashstate); > + err = crypto_shash_export(desc, hashstate); > if (err) > goto err_free; > out: > - fsverity_free_hash_request(alg, req); > kfree(padded_salt); > return hashstate; > > @@ -223,9 +165,7 @@ const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg, > * fsverity_hash_block() - hash a single data or hash block > * @params: the Merkle tree's parameters > * @inode: inode for which the hashing is being done > - * @req: preallocated hash request > - * @page: the page containing the block to hash > - * @offset: the offset of the block within @page > + * @data: virtual address of a buffer containing the block to hash > * @out: output digest, size 'params->digest_size' bytes > * > * Hash a single data or hash block. The hash is salted if a salt is specified > @@ -234,33 +174,24 @@ const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg, > * Return: 0 on success, -errno on failure > */ > int fsverity_hash_block(const struct merkle_tree_params *params, > - const struct inode *inode, struct ahash_request *req, > - struct page *page, unsigned int offset, u8 *out) > + const struct inode *inode, const void *data, u8 *out) > { > - struct scatterlist sg; > - DECLARE_CRYPTO_WAIT(wait); > + SHASH_DESC_ON_STACK(desc, params->hash_alg->tfm); > int err; > > - sg_init_table(&sg, 1); > - sg_set_page(&sg, page, params->block_size, offset); > - ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | > - CRYPTO_TFM_REQ_MAY_BACKLOG, > - crypto_req_done, &wait); > - ahash_request_set_crypt(req, &sg, out, params->block_size); > + desc->tfm = params->hash_alg->tfm; > > if (params->hashstate) { > - err = crypto_ahash_import(req, params->hashstate); > + err = crypto_shash_import(desc, params->hashstate); > if (err) { > fsverity_err(inode, > "Error %d importing hash state", err); > return err; > } > - err = crypto_ahash_finup(req); > + err = crypto_shash_finup(desc, data, params->block_size, out); > } else { > - err = crypto_ahash_digest(req); > + err = crypto_shash_digest(desc, data, params->block_size, out); > } > - > - err = crypto_wait_req(err, &wait); > if (err) > fsverity_err(inode, "Error %d computing block hash", err); > return err; > @@ -273,32 +204,12 @@ int fsverity_hash_block(const struct merkle_tree_params *params, > * @size: size of data to hash, in bytes > * @out: output digest, size 'alg->digest_size' bytes > * > - * Hash some data which is located in physically contiguous memory (i.e. memory > - * allocated by kmalloc(), not by vmalloc()). No salt is used. > - * > * Return: 0 on success, -errno on failure > */ > int fsverity_hash_buffer(struct fsverity_hash_alg *alg, > const void *data, size_t size, u8 *out) > { > - struct ahash_request *req; > - struct scatterlist sg; > - DECLARE_CRYPTO_WAIT(wait); > - int err; > - > - /* This allocation never fails, since it's mempool-backed. */ > - req = fsverity_alloc_hash_request(alg, GFP_KERNEL); > - > - sg_init_one(&sg, data, size); > - ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | > - CRYPTO_TFM_REQ_MAY_BACKLOG, > - crypto_req_done, &wait); > - ahash_request_set_crypt(req, &sg, out, size); > - > - err = crypto_wait_req(crypto_ahash_digest(req), &wait); > - > - fsverity_free_hash_request(alg, req); > - return err; > + return crypto_shash_tfm_digest(alg->tfm, data, size, out); > } > > void __init fsverity_check_hash_algs(void) > diff --git a/fs/verity/verify.c b/fs/verity/verify.c > index e2508222750b3..702500ef1f348 100644 > --- a/fs/verity/verify.c > +++ b/fs/verity/verify.c > @@ -29,21 +29,6 @@ static inline int cmp_hashes(const struct fsverity_info *vi, > return -EBADMSG; > } > > -static bool data_is_zeroed(struct inode *inode, struct page *page, > - unsigned int len, unsigned int offset) > -{ > - void *virt = kmap_local_page(page); > - > - if (memchr_inv(virt + offset, 0, len)) { > - kunmap_local(virt); > - fsverity_err(inode, > - "FILE CORRUPTED! Data past EOF is not zeroed"); > - return false; > - } > - kunmap_local(virt); > - return true; > -} > - > /* > * Returns true if the hash block with index @hblock_idx in the tree, located in > * @hpage, has already been verified. > @@ -122,9 +107,7 @@ static bool is_hash_block_verified(struct fsverity_info *vi, struct page *hpage, > */ > static bool > verify_data_block(struct inode *inode, struct fsverity_info *vi, > - struct ahash_request *req, struct page *data_page, > - u64 data_pos, unsigned int dblock_offset_in_page, > - unsigned long max_ra_pages) > + const void *data, u64 data_pos, unsigned long max_ra_pages) > { > const struct merkle_tree_params *params = &vi->tree_params; > const unsigned int hsize = params->digest_size; > @@ -136,11 +119,11 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, > struct { > /* Page containing the hash block */ > struct page *page; > + /* Mapped address of the hash block (will be within @page) */ > + const void *addr; > /* Index of the hash block in the tree overall */ > unsigned long index; > - /* Byte offset of the hash block within @page */ > - unsigned int offset_in_page; > - /* Byte offset of the wanted hash within @page */ > + /* Byte offset of the wanted hash relative to @addr */ > unsigned int hoffset; > } hblocks[FS_VERITY_MAX_LEVELS]; > /* > @@ -150,6 +133,9 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, > u64 hidx = data_pos >> params->log_blocksize; > int err; > > + /* Up to 1 + FS_VERITY_MAX_LEVELS pages may be mapped at once */ > + BUILD_BUG_ON(1 + FS_VERITY_MAX_LEVELS > KM_MAX_IDX); > + > if (unlikely(data_pos >= inode->i_size)) { > /* > * This can happen in the data page spanning EOF when the Merkle > @@ -159,8 +145,12 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, > * any part past EOF should be all zeroes. Therefore, we need > * to verify that any data blocks fully past EOF are all zeroes. > */ > - return data_is_zeroed(inode, data_page, params->block_size, > - dblock_offset_in_page); > + if (memchr_inv(data, 0, params->block_size)) { > + fsverity_err(inode, > + "FILE CORRUPTED! Data past EOF is not zeroed"); > + return false; > + } > + return true; > } > > /* > @@ -175,6 +165,7 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, > unsigned int hblock_offset_in_page; > unsigned int hoffset; > struct page *hpage; > + const void *haddr; > > /* > * The index of the block in the current level; also the index > @@ -192,10 +183,9 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, > hblock_offset_in_page = > (hblock_idx << params->log_blocksize) & ~PAGE_MASK; > > - /* Byte offset of the hash within the page */ > - hoffset = hblock_offset_in_page + > - ((hidx << params->log_digestsize) & > - (params->block_size - 1)); > + /* Byte offset of the hash within the block */ > + hoffset = (hidx << params->log_digestsize) & > + (params->block_size - 1); > > hpage = inode->i_sb->s_vop->read_merkle_tree_page(inode, > hpage_idx, level == 0 ? min(max_ra_pages, > @@ -207,15 +197,17 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, > err, hpage_idx); > goto out; > } > + haddr = kmap_local_page(hpage) + hblock_offset_in_page; > if (is_hash_block_verified(vi, hpage, hblock_idx)) { > - memcpy_from_page(_want_hash, hpage, hoffset, hsize); > + memcpy(_want_hash, haddr + hoffset, hsize); > want_hash = _want_hash; > + kunmap_local(haddr); > put_page(hpage); > goto descend; > } > hblocks[level].page = hpage; > + hblocks[level].addr = haddr; > hblocks[level].index = hblock_idx; > - hblocks[level].offset_in_page = hblock_offset_in_page; > hblocks[level].hoffset = hoffset; > hidx = next_hidx; > } > @@ -225,13 +217,11 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, > /* Descend the tree verifying hash blocks. */ > for (; level > 0; level--) { > struct page *hpage = hblocks[level - 1].page; > + const void *haddr = hblocks[level - 1].addr; > unsigned long hblock_idx = hblocks[level - 1].index; > - unsigned int hblock_offset_in_page = > - hblocks[level - 1].offset_in_page; > unsigned int hoffset = hblocks[level - 1].hoffset; > > - err = fsverity_hash_block(params, inode, req, hpage, > - hblock_offset_in_page, real_hash); > + err = fsverity_hash_block(params, inode, haddr, real_hash); > if (err) > goto out; > err = cmp_hashes(vi, want_hash, real_hash, data_pos, level - 1); > @@ -246,29 +236,30 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, > set_bit(hblock_idx, vi->hash_block_verified); > else > SetPageChecked(hpage); > - memcpy_from_page(_want_hash, hpage, hoffset, hsize); > + memcpy(_want_hash, haddr + hoffset, hsize); > want_hash = _want_hash; > + kunmap_local(haddr); > put_page(hpage); > } > > /* Finally, verify the data block. */ > - err = fsverity_hash_block(params, inode, req, data_page, > - dblock_offset_in_page, real_hash); > + err = fsverity_hash_block(params, inode, data, real_hash); > if (err) > goto out; > err = cmp_hashes(vi, want_hash, real_hash, data_pos, -1); > out: > - for (; level > 0; level--) > + for (; level > 0; level--) { > + kunmap_local(hblocks[level - 1].addr); > put_page(hblocks[level - 1].page); > - > + } > return err == 0; > } > > static bool > -verify_data_blocks(struct inode *inode, struct fsverity_info *vi, > - struct ahash_request *req, struct folio *data_folio, > +verify_data_blocks(struct inode *inode, struct folio *data_folio, > size_t len, size_t offset, unsigned long max_ra_pages) > { > + struct fsverity_info *vi = inode->i_verity_info; > const unsigned int block_size = vi->tree_params.block_size; > u64 pos = (u64)data_folio->index << PAGE_SHIFT; > > @@ -278,11 +269,14 @@ verify_data_blocks(struct inode *inode, struct fsverity_info *vi, > folio_test_uptodate(data_folio))) > return false; > do { > - struct page *data_page = > - folio_page(data_folio, offset >> PAGE_SHIFT); > - > - if (!verify_data_block(inode, vi, req, data_page, pos + offset, > - offset & ~PAGE_MASK, max_ra_pages)) > + void *data; > + bool valid; > + > + data = kmap_local_folio(data_folio, offset); > + valid = verify_data_block(inode, vi, data, pos + offset, > + max_ra_pages); > + kunmap_local(data); > + if (!valid) > return false; > offset += block_size; > len -= block_size; > @@ -304,19 +298,8 @@ verify_data_blocks(struct inode *inode, struct fsverity_info *vi, > */ > bool fsverity_verify_blocks(struct folio *folio, size_t len, size_t offset) > { > - struct inode *inode = folio->mapping->host; > - struct fsverity_info *vi = inode->i_verity_info; > - struct ahash_request *req; > - bool valid; > - > - /* This allocation never fails, since it's mempool-backed. */ > - req = fsverity_alloc_hash_request(vi->tree_params.hash_alg, GFP_NOFS); > + return verify_data_blocks(folio->mapping->host, folio, len, offset, 0); > > - valid = verify_data_blocks(inode, vi, req, folio, len, offset, 0); > - > - fsverity_free_hash_request(vi->tree_params.hash_alg, req); > - > - return valid; > } > EXPORT_SYMBOL_GPL(fsverity_verify_blocks); > > @@ -338,14 +321,9 @@ EXPORT_SYMBOL_GPL(fsverity_verify_blocks); > void fsverity_verify_bio(struct bio *bio) > { > struct inode *inode = bio_first_page_all(bio)->mapping->host; > - struct fsverity_info *vi = inode->i_verity_info; > - struct ahash_request *req; > struct folio_iter fi; > unsigned long max_ra_pages = 0; > > - /* This allocation never fails, since it's mempool-backed. */ > - req = fsverity_alloc_hash_request(vi->tree_params.hash_alg, GFP_NOFS); > - > if (bio->bi_opf & REQ_RAHEAD) { > /* > * If this bio is for data readahead, then we also do readahead > @@ -360,14 +338,12 @@ void fsverity_verify_bio(struct bio *bio) > } > > bio_for_each_folio_all(fi, bio) { > - if (!verify_data_blocks(inode, vi, req, fi.folio, fi.length, > - fi.offset, max_ra_pages)) { > + if (!verify_data_blocks(inode, fi.folio, fi.length, fi.offset, > + max_ra_pages)) { > bio->bi_status = BLK_STS_IOERR; > break; > } > } > - > - fsverity_free_hash_request(vi->tree_params.hash_alg, req); > } > EXPORT_SYMBOL_GPL(fsverity_verify_bio); > #endif /* CONFIG_BLOCK */ > > base-commit: f1fcbaa18b28dec10281551dfe6ed3a3ed80e3d6 > -- > 2.40.1 >
Hello: This patch was applied to jaegeuk/f2fs.git (dev) by Eric Biggers <ebiggers@google.com>: On Mon, 15 May 2023 22:23:06 -0700 you wrote: > From: Eric Biggers <ebiggers@google.com> > > The "ahash" API, like the other scatterlist-based crypto APIs such as > "skcipher", comes with some well-known limitations. First, it can't > easily be used with vmalloc addresses. Second, the request struct can't > be allocated on the stack. This adds complexity and a possible failure > point that needs to be worked around, e.g. using a mempool. > > [...] Here is the summary with links: - [f2fs-dev,v2] fsverity: use shash API instead of ahash API https://git.kernel.org/jaegeuk/f2fs/c/8fcd94add6c5 You are awesome, thank you!
diff --git a/fs/verity/enable.c b/fs/verity/enable.c index fc4c50e5219dc..bd86b25ac084b 100644 --- a/fs/verity/enable.c +++ b/fs/verity/enable.c @@ -7,6 +7,7 @@ #include "fsverity_private.h" +#include <crypto/hash.h> #include <linux/mount.h> #include <linux/sched/signal.h> #include <linux/uaccess.h> @@ -20,7 +21,7 @@ struct block_buffer { /* Hash a block, writing the result to the next level's pending block buffer. */ static int hash_one_block(struct inode *inode, const struct merkle_tree_params *params, - struct ahash_request *req, struct block_buffer *cur) + struct block_buffer *cur) { struct block_buffer *next = cur + 1; int err; @@ -36,8 +37,7 @@ static int hash_one_block(struct inode *inode, /* Zero-pad the block if it's shorter than the block size. */ memset(&cur->data[cur->filled], 0, params->block_size - cur->filled); - err = fsverity_hash_block(params, inode, req, virt_to_page(cur->data), - offset_in_page(cur->data), + err = fsverity_hash_block(params, inode, cur->data, &next->data[next->filled]); if (err) return err; @@ -76,7 +76,6 @@ static int build_merkle_tree(struct file *filp, struct inode *inode = file_inode(filp); const u64 data_size = inode->i_size; const int num_levels = params->num_levels; - struct ahash_request *req; struct block_buffer _buffers[1 + FS_VERITY_MAX_LEVELS + 1] = {}; struct block_buffer *buffers = &_buffers[1]; unsigned long level_offset[FS_VERITY_MAX_LEVELS]; @@ -90,9 +89,6 @@ static int build_merkle_tree(struct file *filp, return 0; } - /* This allocation never fails, since it's mempool-backed. */ - req = fsverity_alloc_hash_request(params->hash_alg, GFP_KERNEL); - /* * Allocate the block buffers. Buffer "-1" is for data blocks. * Buffers 0 <= level < num_levels are for the actual tree levels. @@ -130,7 +126,7 @@ static int build_merkle_tree(struct file *filp, fsverity_err(inode, "Short read of file data"); goto out; } - err = hash_one_block(inode, params, req, &buffers[-1]); + err = hash_one_block(inode, params, &buffers[-1]); if (err) goto out; for (level = 0; level < num_levels; level++) { @@ -141,8 +137,7 @@ static int build_merkle_tree(struct file *filp, } /* Next block at @level is full */ - err = hash_one_block(inode, params, req, - &buffers[level]); + err = hash_one_block(inode, params, &buffers[level]); if (err) goto out; err = write_merkle_tree_block(inode, @@ -162,8 +157,7 @@ static int build_merkle_tree(struct file *filp, /* Finish all nonempty pending tree blocks. */ for (level = 0; level < num_levels; level++) { if (buffers[level].filled != 0) { - err = hash_one_block(inode, params, req, - &buffers[level]); + err = hash_one_block(inode, params, &buffers[level]); if (err) goto out; err = write_merkle_tree_block(inode, @@ -183,7 +177,6 @@ static int build_merkle_tree(struct file *filp, out: for (level = -1; level < num_levels; level++) kfree(buffers[level].data); - fsverity_free_hash_request(params->hash_alg, req); return err; } diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h index d34dcc033d723..8527beca2a454 100644 --- a/fs/verity/fsverity_private.h +++ b/fs/verity/fsverity_private.h @@ -11,9 +11,6 @@ #define pr_fmt(fmt) "fs-verity: " fmt #include <linux/fsverity.h> -#include <linux/mempool.h> - -struct ahash_request; /* * Implementation limit: maximum depth of the Merkle tree. For now 8 is plenty; @@ -23,11 +20,10 @@ struct ahash_request; /* A hash algorithm supported by fs-verity */ struct fsverity_hash_alg { - struct crypto_ahash *tfm; /* hash tfm, allocated on demand */ + struct crypto_shash *tfm; /* hash tfm, allocated on demand */ const char *name; /* crypto API name, e.g. sha256 */ unsigned int digest_size; /* digest size in bytes, e.g. 32 for SHA-256 */ unsigned int block_size; /* block size in bytes, e.g. 64 for SHA-256 */ - mempool_t req_pool; /* mempool with a preallocated hash request */ /* * The HASH_ALGO_* constant for this algorithm. This is different from * FS_VERITY_HASH_ALG_*, which uses a different numbering scheme. @@ -85,15 +81,10 @@ extern struct fsverity_hash_alg fsverity_hash_algs[]; struct fsverity_hash_alg *fsverity_get_hash_alg(const struct inode *inode, unsigned int num); -struct ahash_request *fsverity_alloc_hash_request(struct fsverity_hash_alg *alg, - gfp_t gfp_flags); -void fsverity_free_hash_request(struct fsverity_hash_alg *alg, - struct ahash_request *req); const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg, const u8 *salt, size_t salt_size); int fsverity_hash_block(const struct merkle_tree_params *params, - const struct inode *inode, struct ahash_request *req, - struct page *page, unsigned int offset, u8 *out); + const struct inode *inode, const void *data, u8 *out); int fsverity_hash_buffer(struct fsverity_hash_alg *alg, const void *data, size_t size, u8 *out); void __init fsverity_check_hash_algs(void); diff --git a/fs/verity/hash_algs.c b/fs/verity/hash_algs.c index ea00dbedf756b..e7e982412e23a 100644 --- a/fs/verity/hash_algs.c +++ b/fs/verity/hash_algs.c @@ -8,7 +8,6 @@ #include "fsverity_private.h" #include <crypto/hash.h> -#include <linux/scatterlist.h> /* The hash algorithms supported by fs-verity */ struct fsverity_hash_alg fsverity_hash_algs[] = { @@ -44,7 +43,7 @@ struct fsverity_hash_alg *fsverity_get_hash_alg(const struct inode *inode, unsigned int num) { struct fsverity_hash_alg *alg; - struct crypto_ahash *tfm; + struct crypto_shash *tfm; int err; if (num >= ARRAY_SIZE(fsverity_hash_algs) || @@ -63,11 +62,7 @@ struct fsverity_hash_alg *fsverity_get_hash_alg(const struct inode *inode, if (alg->tfm != NULL) goto out_unlock; - /* - * Using the shash API would make things a bit simpler, but the ahash - * API is preferable as it allows the use of crypto accelerators. - */ - tfm = crypto_alloc_ahash(alg->name, 0, 0); + tfm = crypto_alloc_shash(alg->name, 0, 0); if (IS_ERR(tfm)) { if (PTR_ERR(tfm) == -ENOENT) { fsverity_warn(inode, @@ -84,68 +79,26 @@ struct fsverity_hash_alg *fsverity_get_hash_alg(const struct inode *inode, } err = -EINVAL; - if (WARN_ON_ONCE(alg->digest_size != crypto_ahash_digestsize(tfm))) + if (WARN_ON_ONCE(alg->digest_size != crypto_shash_digestsize(tfm))) goto err_free_tfm; - if (WARN_ON_ONCE(alg->block_size != crypto_ahash_blocksize(tfm))) - goto err_free_tfm; - - err = mempool_init_kmalloc_pool(&alg->req_pool, 1, - sizeof(struct ahash_request) + - crypto_ahash_reqsize(tfm)); - if (err) + if (WARN_ON_ONCE(alg->block_size != crypto_shash_blocksize(tfm))) goto err_free_tfm; pr_info("%s using implementation \"%s\"\n", - alg->name, crypto_ahash_driver_name(tfm)); + alg->name, crypto_shash_driver_name(tfm)); /* pairs with smp_load_acquire() above */ smp_store_release(&alg->tfm, tfm); goto out_unlock; err_free_tfm: - crypto_free_ahash(tfm); + crypto_free_shash(tfm); alg = ERR_PTR(err); out_unlock: mutex_unlock(&fsverity_hash_alg_init_mutex); return alg; } -/** - * fsverity_alloc_hash_request() - allocate a hash request object - * @alg: the hash algorithm for which to allocate the request - * @gfp_flags: memory allocation flags - * - * This is mempool-backed, so this never fails if __GFP_DIRECT_RECLAIM is set in - * @gfp_flags. However, in that case this might need to wait for all - * previously-allocated requests to be freed. So to avoid deadlocks, callers - * must never need multiple requests at a time to make forward progress. - * - * Return: the request object on success; NULL on failure (but see above) - */ -struct ahash_request *fsverity_alloc_hash_request(struct fsverity_hash_alg *alg, - gfp_t gfp_flags) -{ - struct ahash_request *req = mempool_alloc(&alg->req_pool, gfp_flags); - - if (req) - ahash_request_set_tfm(req, alg->tfm); - return req; -} - -/** - * fsverity_free_hash_request() - free a hash request object - * @alg: the hash algorithm - * @req: the hash request object to free - */ -void fsverity_free_hash_request(struct fsverity_hash_alg *alg, - struct ahash_request *req) -{ - if (req) { - ahash_request_zero(req); - mempool_free(req, &alg->req_pool); - } -} - /** * fsverity_prepare_hash_state() - precompute the initial hash state * @alg: hash algorithm @@ -159,23 +112,20 @@ const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg, const u8 *salt, size_t salt_size) { u8 *hashstate = NULL; - struct ahash_request *req = NULL; + SHASH_DESC_ON_STACK(desc, alg->tfm); u8 *padded_salt = NULL; size_t padded_salt_size; - struct scatterlist sg; - DECLARE_CRYPTO_WAIT(wait); int err; + desc->tfm = alg->tfm; + if (salt_size == 0) return NULL; - hashstate = kmalloc(crypto_ahash_statesize(alg->tfm), GFP_KERNEL); + hashstate = kmalloc(crypto_shash_statesize(alg->tfm), GFP_KERNEL); if (!hashstate) return ERR_PTR(-ENOMEM); - /* This allocation never fails, since it's mempool-backed. */ - req = fsverity_alloc_hash_request(alg, GFP_KERNEL); - /* * Zero-pad the salt to the next multiple of the input size of the hash * algorithm's compression function, e.g. 64 bytes for SHA-256 or 128 @@ -190,26 +140,18 @@ const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg, goto err_free; } memcpy(padded_salt, salt, salt_size); - - sg_init_one(&sg, padded_salt, padded_salt_size); - ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | - CRYPTO_TFM_REQ_MAY_BACKLOG, - crypto_req_done, &wait); - ahash_request_set_crypt(req, &sg, NULL, padded_salt_size); - - err = crypto_wait_req(crypto_ahash_init(req), &wait); + err = crypto_shash_init(desc); if (err) goto err_free; - err = crypto_wait_req(crypto_ahash_update(req), &wait); + err = crypto_shash_update(desc, padded_salt, padded_salt_size); if (err) goto err_free; - err = crypto_ahash_export(req, hashstate); + err = crypto_shash_export(desc, hashstate); if (err) goto err_free; out: - fsverity_free_hash_request(alg, req); kfree(padded_salt); return hashstate; @@ -223,9 +165,7 @@ const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg, * fsverity_hash_block() - hash a single data or hash block * @params: the Merkle tree's parameters * @inode: inode for which the hashing is being done - * @req: preallocated hash request - * @page: the page containing the block to hash - * @offset: the offset of the block within @page + * @data: virtual address of a buffer containing the block to hash * @out: output digest, size 'params->digest_size' bytes * * Hash a single data or hash block. The hash is salted if a salt is specified @@ -234,33 +174,24 @@ const u8 *fsverity_prepare_hash_state(struct fsverity_hash_alg *alg, * Return: 0 on success, -errno on failure */ int fsverity_hash_block(const struct merkle_tree_params *params, - const struct inode *inode, struct ahash_request *req, - struct page *page, unsigned int offset, u8 *out) + const struct inode *inode, const void *data, u8 *out) { - struct scatterlist sg; - DECLARE_CRYPTO_WAIT(wait); + SHASH_DESC_ON_STACK(desc, params->hash_alg->tfm); int err; - sg_init_table(&sg, 1); - sg_set_page(&sg, page, params->block_size, offset); - ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | - CRYPTO_TFM_REQ_MAY_BACKLOG, - crypto_req_done, &wait); - ahash_request_set_crypt(req, &sg, out, params->block_size); + desc->tfm = params->hash_alg->tfm; if (params->hashstate) { - err = crypto_ahash_import(req, params->hashstate); + err = crypto_shash_import(desc, params->hashstate); if (err) { fsverity_err(inode, "Error %d importing hash state", err); return err; } - err = crypto_ahash_finup(req); + err = crypto_shash_finup(desc, data, params->block_size, out); } else { - err = crypto_ahash_digest(req); + err = crypto_shash_digest(desc, data, params->block_size, out); } - - err = crypto_wait_req(err, &wait); if (err) fsverity_err(inode, "Error %d computing block hash", err); return err; @@ -273,32 +204,12 @@ int fsverity_hash_block(const struct merkle_tree_params *params, * @size: size of data to hash, in bytes * @out: output digest, size 'alg->digest_size' bytes * - * Hash some data which is located in physically contiguous memory (i.e. memory - * allocated by kmalloc(), not by vmalloc()). No salt is used. - * * Return: 0 on success, -errno on failure */ int fsverity_hash_buffer(struct fsverity_hash_alg *alg, const void *data, size_t size, u8 *out) { - struct ahash_request *req; - struct scatterlist sg; - DECLARE_CRYPTO_WAIT(wait); - int err; - - /* This allocation never fails, since it's mempool-backed. */ - req = fsverity_alloc_hash_request(alg, GFP_KERNEL); - - sg_init_one(&sg, data, size); - ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP | - CRYPTO_TFM_REQ_MAY_BACKLOG, - crypto_req_done, &wait); - ahash_request_set_crypt(req, &sg, out, size); - - err = crypto_wait_req(crypto_ahash_digest(req), &wait); - - fsverity_free_hash_request(alg, req); - return err; + return crypto_shash_tfm_digest(alg->tfm, data, size, out); } void __init fsverity_check_hash_algs(void) diff --git a/fs/verity/verify.c b/fs/verity/verify.c index e2508222750b3..702500ef1f348 100644 --- a/fs/verity/verify.c +++ b/fs/verity/verify.c @@ -29,21 +29,6 @@ static inline int cmp_hashes(const struct fsverity_info *vi, return -EBADMSG; } -static bool data_is_zeroed(struct inode *inode, struct page *page, - unsigned int len, unsigned int offset) -{ - void *virt = kmap_local_page(page); - - if (memchr_inv(virt + offset, 0, len)) { - kunmap_local(virt); - fsverity_err(inode, - "FILE CORRUPTED! Data past EOF is not zeroed"); - return false; - } - kunmap_local(virt); - return true; -} - /* * Returns true if the hash block with index @hblock_idx in the tree, located in * @hpage, has already been verified. @@ -122,9 +107,7 @@ static bool is_hash_block_verified(struct fsverity_info *vi, struct page *hpage, */ static bool verify_data_block(struct inode *inode, struct fsverity_info *vi, - struct ahash_request *req, struct page *data_page, - u64 data_pos, unsigned int dblock_offset_in_page, - unsigned long max_ra_pages) + const void *data, u64 data_pos, unsigned long max_ra_pages) { const struct merkle_tree_params *params = &vi->tree_params; const unsigned int hsize = params->digest_size; @@ -136,11 +119,11 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, struct { /* Page containing the hash block */ struct page *page; + /* Mapped address of the hash block (will be within @page) */ + const void *addr; /* Index of the hash block in the tree overall */ unsigned long index; - /* Byte offset of the hash block within @page */ - unsigned int offset_in_page; - /* Byte offset of the wanted hash within @page */ + /* Byte offset of the wanted hash relative to @addr */ unsigned int hoffset; } hblocks[FS_VERITY_MAX_LEVELS]; /* @@ -150,6 +133,9 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, u64 hidx = data_pos >> params->log_blocksize; int err; + /* Up to 1 + FS_VERITY_MAX_LEVELS pages may be mapped at once */ + BUILD_BUG_ON(1 + FS_VERITY_MAX_LEVELS > KM_MAX_IDX); + if (unlikely(data_pos >= inode->i_size)) { /* * This can happen in the data page spanning EOF when the Merkle @@ -159,8 +145,12 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, * any part past EOF should be all zeroes. Therefore, we need * to verify that any data blocks fully past EOF are all zeroes. */ - return data_is_zeroed(inode, data_page, params->block_size, - dblock_offset_in_page); + if (memchr_inv(data, 0, params->block_size)) { + fsverity_err(inode, + "FILE CORRUPTED! Data past EOF is not zeroed"); + return false; + } + return true; } /* @@ -175,6 +165,7 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, unsigned int hblock_offset_in_page; unsigned int hoffset; struct page *hpage; + const void *haddr; /* * The index of the block in the current level; also the index @@ -192,10 +183,9 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, hblock_offset_in_page = (hblock_idx << params->log_blocksize) & ~PAGE_MASK; - /* Byte offset of the hash within the page */ - hoffset = hblock_offset_in_page + - ((hidx << params->log_digestsize) & - (params->block_size - 1)); + /* Byte offset of the hash within the block */ + hoffset = (hidx << params->log_digestsize) & + (params->block_size - 1); hpage = inode->i_sb->s_vop->read_merkle_tree_page(inode, hpage_idx, level == 0 ? min(max_ra_pages, @@ -207,15 +197,17 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, err, hpage_idx); goto out; } + haddr = kmap_local_page(hpage) + hblock_offset_in_page; if (is_hash_block_verified(vi, hpage, hblock_idx)) { - memcpy_from_page(_want_hash, hpage, hoffset, hsize); + memcpy(_want_hash, haddr + hoffset, hsize); want_hash = _want_hash; + kunmap_local(haddr); put_page(hpage); goto descend; } hblocks[level].page = hpage; + hblocks[level].addr = haddr; hblocks[level].index = hblock_idx; - hblocks[level].offset_in_page = hblock_offset_in_page; hblocks[level].hoffset = hoffset; hidx = next_hidx; } @@ -225,13 +217,11 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, /* Descend the tree verifying hash blocks. */ for (; level > 0; level--) { struct page *hpage = hblocks[level - 1].page; + const void *haddr = hblocks[level - 1].addr; unsigned long hblock_idx = hblocks[level - 1].index; - unsigned int hblock_offset_in_page = - hblocks[level - 1].offset_in_page; unsigned int hoffset = hblocks[level - 1].hoffset; - err = fsverity_hash_block(params, inode, req, hpage, - hblock_offset_in_page, real_hash); + err = fsverity_hash_block(params, inode, haddr, real_hash); if (err) goto out; err = cmp_hashes(vi, want_hash, real_hash, data_pos, level - 1); @@ -246,29 +236,30 @@ verify_data_block(struct inode *inode, struct fsverity_info *vi, set_bit(hblock_idx, vi->hash_block_verified); else SetPageChecked(hpage); - memcpy_from_page(_want_hash, hpage, hoffset, hsize); + memcpy(_want_hash, haddr + hoffset, hsize); want_hash = _want_hash; + kunmap_local(haddr); put_page(hpage); } /* Finally, verify the data block. */ - err = fsverity_hash_block(params, inode, req, data_page, - dblock_offset_in_page, real_hash); + err = fsverity_hash_block(params, inode, data, real_hash); if (err) goto out; err = cmp_hashes(vi, want_hash, real_hash, data_pos, -1); out: - for (; level > 0; level--) + for (; level > 0; level--) { + kunmap_local(hblocks[level - 1].addr); put_page(hblocks[level - 1].page); - + } return err == 0; } static bool -verify_data_blocks(struct inode *inode, struct fsverity_info *vi, - struct ahash_request *req, struct folio *data_folio, +verify_data_blocks(struct inode *inode, struct folio *data_folio, size_t len, size_t offset, unsigned long max_ra_pages) { + struct fsverity_info *vi = inode->i_verity_info; const unsigned int block_size = vi->tree_params.block_size; u64 pos = (u64)data_folio->index << PAGE_SHIFT; @@ -278,11 +269,14 @@ verify_data_blocks(struct inode *inode, struct fsverity_info *vi, folio_test_uptodate(data_folio))) return false; do { - struct page *data_page = - folio_page(data_folio, offset >> PAGE_SHIFT); - - if (!verify_data_block(inode, vi, req, data_page, pos + offset, - offset & ~PAGE_MASK, max_ra_pages)) + void *data; + bool valid; + + data = kmap_local_folio(data_folio, offset); + valid = verify_data_block(inode, vi, data, pos + offset, + max_ra_pages); + kunmap_local(data); + if (!valid) return false; offset += block_size; len -= block_size; @@ -304,19 +298,8 @@ verify_data_blocks(struct inode *inode, struct fsverity_info *vi, */ bool fsverity_verify_blocks(struct folio *folio, size_t len, size_t offset) { - struct inode *inode = folio->mapping->host; - struct fsverity_info *vi = inode->i_verity_info; - struct ahash_request *req; - bool valid; - - /* This allocation never fails, since it's mempool-backed. */ - req = fsverity_alloc_hash_request(vi->tree_params.hash_alg, GFP_NOFS); + return verify_data_blocks(folio->mapping->host, folio, len, offset, 0); - valid = verify_data_blocks(inode, vi, req, folio, len, offset, 0); - - fsverity_free_hash_request(vi->tree_params.hash_alg, req); - - return valid; } EXPORT_SYMBOL_GPL(fsverity_verify_blocks); @@ -338,14 +321,9 @@ EXPORT_SYMBOL_GPL(fsverity_verify_blocks); void fsverity_verify_bio(struct bio *bio) { struct inode *inode = bio_first_page_all(bio)->mapping->host; - struct fsverity_info *vi = inode->i_verity_info; - struct ahash_request *req; struct folio_iter fi; unsigned long max_ra_pages = 0; - /* This allocation never fails, since it's mempool-backed. */ - req = fsverity_alloc_hash_request(vi->tree_params.hash_alg, GFP_NOFS); - if (bio->bi_opf & REQ_RAHEAD) { /* * If this bio is for data readahead, then we also do readahead @@ -360,14 +338,12 @@ void fsverity_verify_bio(struct bio *bio) } bio_for_each_folio_all(fi, bio) { - if (!verify_data_blocks(inode, vi, req, fi.folio, fi.length, - fi.offset, max_ra_pages)) { + if (!verify_data_blocks(inode, fi.folio, fi.length, fi.offset, + max_ra_pages)) { bio->bi_status = BLK_STS_IOERR; break; } } - - fsverity_free_hash_request(vi->tree_params.hash_alg, req); } EXPORT_SYMBOL_GPL(fsverity_verify_bio); #endif /* CONFIG_BLOCK */