[PATCH net-next 01/23] keys: Provide the original description to the key preparser

[David Howells]

Provide the proposed description (add key) or the original description
(update/instantiate key) when preparsing a key so that the key type can
validate it against the data.

This is important for rxrpc server keys as we need to check that they have
the right amount of key material present - and it's better to do that when
the key is loaded rather than deep in trying to process a response packet.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
cc: keyrings@xxxxxxxxxxxxxxx
---

 include/linux/key-type.h |    1 +
 security/keys/key.c      |    2 ++
 2 files changed, 3 insertions(+)

diff --git a/include/linux/key-type.h b/include/linux/key-type.h
index 2ab2d6d6aeab..7d985a1dfe4a 100644
--- a/include/linux/key-type.h
+++ b/include/linux/key-type.h
@@ -29,6 +29,7 @@ struct kernel_pkey_params;
  * clear the contents.
  */
 struct key_preparsed_payload {
+	const char	*orig_description; /* Actual or proposed description (maybe NULL) */
 	char		*description;	/* Proposed key description (or NULL) */
 	union key_payload payload;	/* Proposed payload */
 	const void	*data;		/* Raw data */
diff --git a/security/keys/key.c b/security/keys/key.c
index e282c6179b21..ebe752b137aa 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -504,6 +504,7 @@ int key_instantiate_and_link(struct key *key,
 	int ret;
 
 	memset(&prep, 0, sizeof(prep));
+	prep.orig_description = key->description;
 	prep.data = data;
 	prep.datalen = datalen;
 	prep.quotalen = key->type->def_datalen;
@@ -854,6 +855,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
 		goto error_put_type;
 
 	memset(&prep, 0, sizeof(prep));
+	prep.orig_description = description;
 	prep.data = payload;
 	prep.datalen = plen;
 	prep.quotalen = index_key.type->def_datalen;