[PATCH 4.19 167/219] crypto: virtio - deal with unsupported input sizes

From: Greg Kroah-Hartman
Date: Sun Dec 29 2019 - 12:44:06 EST


From: Ard Biesheuvel <ardb@xxxxxxxxxx>

[ Upstream commit 19c5da7d4a2662e85ea67d2d81df57e038fde3ab ]

Return -EINVAL for input sizes that are not a multiple of the AES
block size, since they are not supported by our CBC chaining mode.

While at it, remove the pr_err() that reports unsupported key sizes
being used: we shouldn't spam the kernel log with that.

Fixes: dbaf0624ffa5 ("crypto: add virtio-crypto driver")
Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Cc: Jason Wang <jasowang@xxxxxxxxxx>
Cc: Gonglei <arei.gonglei@xxxxxxxxxx>
Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/crypto/virtio/virtio_crypto_algs.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/virtio/virtio_crypto_algs.c b/drivers/crypto/virtio/virtio_crypto_algs.c
index 2c573d1aaa64..523b712770ac 100644
--- a/drivers/crypto/virtio/virtio_crypto_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -117,8 +117,6 @@ virtio_crypto_alg_validate_key(int key_len, uint32_t *alg)
*alg = VIRTIO_CRYPTO_CIPHER_AES_CBC;
break;
default:
- pr_err("virtio_crypto: Unsupported key length: %d\n",
- key_len);
return -EINVAL;
}
return 0;
@@ -498,6 +496,11 @@ static int virtio_crypto_ablkcipher_encrypt(struct ablkcipher_request *req)
/* Use the first data virtqueue as default */
struct data_queue *data_vq = &vcrypto->data_vq[0];

+ if (!req->nbytes)
+ return 0;
+ if (req->nbytes % AES_BLOCK_SIZE)
+ return -EINVAL;
+
vc_req->dataq = data_vq;
vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
vc_sym_req->ablkcipher_ctx = ctx;
@@ -518,6 +521,11 @@ static int virtio_crypto_ablkcipher_decrypt(struct ablkcipher_request *req)
/* Use the first data virtqueue as default */
struct data_queue *data_vq = &vcrypto->data_vq[0];

+ if (!req->nbytes)
+ return 0;
+ if (req->nbytes % AES_BLOCK_SIZE)
+ return -EINVAL;
+
vc_req->dataq = data_vq;
vc_req->alg_cb = virtio_crypto_dataq_sym_callback;
vc_sym_req->ablkcipher_ctx = ctx;
--
2.20.1