On Fri, Jan 20, 2023 at 02:21:04PM -0500, Paul Moore wrote:

On Wed, Dec 7, 2022 at 5:55 AM Roberto Sassu
[off-list ref] wrote:

quoted

From: Roberto Sassu <roberto.sassu@huawei.com>

public_key_verify_signature() calls sg_set_buf() to set the signature and
digest for the signature verification.

As sg_set_buf() requires the buffer to be in physically contiguous memory,
see commit ac4e97abce9b8 ("scatterlist: sg_set_buf() argument must be in
linear mapping"), mention that in a comment for the signature and digest
fields of the public_key_signature structure.

Link: https://lore.kernel.org/linux-integrity/Y4pIpxbjBdajymBJ@sol.localdomain/ (local)
Suggested-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 include/crypto/public_key.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

This seems especially important considering the BUG_ON that could be triggered.

David, are you going to pick this up?

Reviewed-by: Paul Moore <paul@paul-moore.com>

quoted

diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 68f7aa2a7e55..6d623e063034 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h

@@ -37,8 +37,8 @@ extern void public_key_free(struct public_key *key);
  */
 struct public_key_signature {
        struct asymmetric_key_id *auth_ids[3];
-       u8 *s;                  /* Signature */
-       u8 *digest;
+       u8 *s;                  /* Signature (in physically contiguous mem) */
+       u8 *digest;             /* Digest (in physically contiguous mem) */
        u32 s_size;             /* Number of bytes in signature */
        u32 digest_size;        /* Number of bytes in digest */
        const char *pkey_algo;
--

2.25.1

This patch has been superseded by
"KEYS: asymmetric: Copy sig and digest in public_key_verify_signature()"
(https://lore.kernel.org/r/20221227142740.2807136-1-roberto.sassu@huaweicloud.com (local)).

- Eric