net: sctp: sctp_auth_make_key_vector: use sctp_auth_create_key

In sctp_auth_make_key_vector, we allocate a temporary sctp_auth_bytes
structure with kmalloc instead of the sctp_auth_create_key allocator.
Change this to sctp_auth_create_key as it is the case everywhere else,
so that we also can properly free it via sctp_auth_key_put. This makes
it easier for future code changes in the structure and allocator itself,
since a single API is consistently used for this purpose. Also, by
using sctp_auth_create_key we're doing sanity checks over the arguments.
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Acked-by: NVlad Yasevich <vyasevich@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sctp/auth.c

@@ -209,12 +209,10 @@ static struct sctp_auth_bytes *sctp_auth_make_key_vector(
 
 	len = random_len + hmacs_len + chunks_len;
 
-	new = kmalloc(sizeof(struct sctp_auth_bytes) + len, gfp);
+	new = sctp_auth_create_key(len, gfp);
 	if (!new)
 		return NULL;
 
-	new->len = len;
-
 	memcpy(new->data, random, random_len);
 	offset += random_len;
 
@@ -353,8 +351,8 @@ static struct sctp_auth_bytes *sctp_auth_asoc_create_secret(
 	secret = sctp_auth_asoc_set_secret(ep_key, first_vector, last_vector,
 					    gfp);
 out:
-	kfree(local_key_vector);
-	kfree(peer_key_vector);
+	sctp_auth_key_put(local_key_vector);
+	sctp_auth_key_put(peer_key_vector);
 
 	return secret;
 }