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authorEric Biggers <ebiggers@google.com>2021-01-15 19:18:15 +0100
committerEric Biggers <ebiggers@google.com>2021-02-07 23:51:09 +0100
commitfab634c4de4604aefaaa9dc25d0e1a2cb7a961ab (patch)
tree48f94c89cb86c43b472738346720887757e839e2 /fs/verity
parentfs-verity: factor out fsverity_get_descriptor() (diff)
downloadlinux-fab634c4de4604aefaaa9dc25d0e1a2cb7a961ab.tar.xz
linux-fab634c4de4604aefaaa9dc25d0e1a2cb7a961ab.zip
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 <victorhsieh@google.com> Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org> Reviewed-by: Amy Parker <enbyamy@gmail.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Eric Biggers <ebiggers@google.com>
Diffstat (limited to 'fs/verity')
-rw-r--r--fs/verity/fsverity_private.h6
-rw-r--r--fs/verity/open.c3
-rw-r--r--fs/verity/signature.c20
3 files changed, 10 insertions, 19 deletions
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);