From fab634c4de4604aefaaa9dc25d0e1a2cb7a961ab Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 15 Jan 2021 10:18:15 -0800 Subject: fs-verity: don't pass whole descriptor to fsverity_verify_signature() Now that fsverity_get_descriptor() validates the sig_size field, fsverity_verify_signature() doesn't need to do it. Just change the prototype of fsverity_verify_signature() to take the signature directly rather than take a fsverity_descriptor. Link: https://lore.kernel.org/r/20210115181819.34732-3-ebiggers@kernel.org Reviewed-by: Victor Hsieh Reviewed-by: Jaegeuk Kim Reviewed-by: Amy Parker Reviewed-by: Chao Yu Signed-off-by: Eric Biggers --- fs/verity/fsverity_private.h | 6 ++---- fs/verity/open.c | 3 ++- fs/verity/signature.c | 20 ++++++-------------- 3 files changed, 10 insertions(+), 19 deletions(-) (limited to 'fs/verity') diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h index 6c9caccc0602..a7920434bae5 100644 --- a/fs/verity/fsverity_private.h +++ b/fs/verity/fsverity_private.h @@ -140,15 +140,13 @@ void __init fsverity_exit_info_cache(void); #ifdef CONFIG_FS_VERITY_BUILTIN_SIGNATURES int fsverity_verify_signature(const struct fsverity_info *vi, - const struct fsverity_descriptor *desc, - size_t desc_size); + const u8 *signature, size_t sig_size); int __init fsverity_init_signature(void); #else /* !CONFIG_FS_VERITY_BUILTIN_SIGNATURES */ static inline int fsverity_verify_signature(const struct fsverity_info *vi, - const struct fsverity_descriptor *desc, - size_t desc_size) + const u8 *signature, size_t sig_size) { return 0; } diff --git a/fs/verity/open.c b/fs/verity/open.c index a987bb785e9b..60ff8af7219f 100644 --- a/fs/verity/open.c +++ b/fs/verity/open.c @@ -181,7 +181,8 @@ struct fsverity_info *fsverity_create_info(const struct inode *inode, vi->tree_params.hash_alg->name, vi->tree_params.digest_size, vi->file_digest); - err = fsverity_verify_signature(vi, desc, desc_size); + err = fsverity_verify_signature(vi, desc->signature, + le32_to_cpu(desc->sig_size)); out: if (err) { fsverity_free_info(vi); diff --git a/fs/verity/signature.c b/fs/verity/signature.c index 012468eda2a7..143a530a8008 100644 --- a/fs/verity/signature.c +++ b/fs/verity/signature.c @@ -29,21 +29,19 @@ static struct key *fsverity_keyring; /** * fsverity_verify_signature() - check a verity file's signature * @vi: the file's fsverity_info - * @desc: the file's fsverity_descriptor - * @desc_size: size of @desc + * @signature: the file's built-in signature + * @sig_size: size of signature in bytes, or 0 if no signature * - * If the file's fs-verity descriptor includes a signature of the file digest, - * verify it against the certificates in the fs-verity keyring. + * If the file includes a signature of its fs-verity file digest, verify it + * against the certificates in the fs-verity keyring. * * Return: 0 on success (signature valid or not required); -errno on failure */ int fsverity_verify_signature(const struct fsverity_info *vi, - const struct fsverity_descriptor *desc, - size_t desc_size) + const u8 *signature, size_t sig_size) { const struct inode *inode = vi->inode; const struct fsverity_hash_alg *hash_alg = vi->tree_params.hash_alg; - const u32 sig_size = le32_to_cpu(desc->sig_size); struct fsverity_formatted_digest *d; int err; @@ -56,11 +54,6 @@ int fsverity_verify_signature(const struct fsverity_info *vi, return 0; } - if (sig_size > desc_size - sizeof(*desc)) { - fsverity_err(inode, "Signature overflows verity descriptor"); - return -EBADMSG; - } - d = kzalloc(sizeof(*d) + hash_alg->digest_size, GFP_KERNEL); if (!d) return -ENOMEM; @@ -70,8 +63,7 @@ int fsverity_verify_signature(const struct fsverity_info *vi, memcpy(d->digest, vi->file_digest, hash_alg->digest_size); err = verify_pkcs7_signature(d, sizeof(*d) + hash_alg->digest_size, - desc->signature, sig_size, - fsverity_keyring, + signature, sig_size, fsverity_keyring, VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL); kfree(d); -- cgit v1.2.3