Re: [PATCH v2 6/9] crypto: virtio: Add req_data with structure virtio_crypto_sym_request

[Bibo Mao]

On 2025/12/4 下午8:46, Michael S. Tsirkin wrote:
On Thu, Dec 04, 2025 at 07:22:23PM +0800, Bibo Mao wrote:
With normal encrypt/decrypt workflow, req_data with struct type
virtio_crypto_op_data_req will be allocated. Here put req_data in
virtio_crypto_sym_request, it is pre-allocated when encrypt/decrypt
interface is called.

Signed-off-by: Bibo Mao <maob...@loongson.cn>
---
  drivers/crypto/virtio/virtio_crypto_core.c          |  3 ++-
  drivers/crypto/virtio/virtio_crypto_skcipher_algs.c | 12 +++---------
  2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/crypto/virtio/virtio_crypto_core.c 
b/drivers/crypto/virtio/virtio_crypto_core.c
index ccc6b5c1b24b..e60ad1d94e7f 100644
--- a/drivers/crypto/virtio/virtio_crypto_core.c
+++ b/drivers/crypto/virtio/virtio_crypto_core.c
@@ -17,7 +17,8 @@ void
  virtcrypto_clear_request(struct virtio_crypto_request *vc_req)
  {
        if (vc_req) {
-               kfree_sensitive(vc_req->req_data);
+               if (vc_req->req_data)
+                       kfree_sensitive(vc_req->req_data);

kfree of NULL is a nop, why make this change?
Will keep it unchanged in next version.


                kfree(vc_req->sgs);
        }
  }
diff --git a/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c 
b/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c
index 7b3f21a40d78..a7c7c726e6d9 100644
--- a/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_skcipher_algs.c
@@ -26,6 +26,7 @@ struct virtio_crypto_skcipher_ctx {
  
  struct virtio_crypto_sym_request {
        struct virtio_crypto_request base;
+       struct virtio_crypto_op_data_req req_data;
  
  	/* Cipher or aead */
        uint32_t type;
@@ -350,14 +351,8 @@ __virtio_crypto_skcipher_do_req(struct 
virtio_crypto_sym_request *vc_sym_req,
        if (!sgs)
                return -ENOMEM;
  
-	req_data = kzalloc_node(sizeof(*req_data), GFP_KERNEL,
-                               dev_to_node(&vcrypto->vdev->dev));
-       if (!req_data) {
-               kfree(sgs);
-               return -ENOMEM;
-       }
-
-       vc_req->req_data = req_data;
+       req_data = &vc_sym_req->req_data;
+       vc_req->req_data = NULL;
        vc_sym_req->type = VIRTIO_CRYPTO_SYM_OP_CIPHER;
        /* Head of operation */
        if (vc_sym_req->encrypt) {
@@ -450,7 +445,6 @@ __virtio_crypto_skcipher_do_req(struct 
virtio_crypto_sym_request *vc_sym_req,
  free_iv:
        kfree_sensitive(iv);
  free:
-       kfree_sensitive(req_data);


So the request is no longer erased with memset on error. Is that not
a problem?
I do not know why req_data is sensitive data here, it is only control 
command, key and IV data is not in req_data.

Regards
Bibo Mao

        kfree(sgs);
        return err;
  }
--
2.39.3