[PATCH 5.4 315/434] crypto: virtio - deal with unsupported input sizes

Greg Kroah-Hartman
2019-12-29T17:54:03Z

From: Ard Biesheuvel <ardb@kernel.org>

[ 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@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Gonglei <arei.gonglei@huawei.com>
Cc: virtualization@lists.linux-foundation.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 42d19205166b..673fb29fda53 100644
--- a/drivers/crypto/virtio/virtio_crypto_algs.c
+++ b/drivers/crypto/virtio/virtio_crypto_algs.c
@@ -105,8 +105,6 @@ 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;
@@ -484,6 +482,11 @@ 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;
@@ -504,6 +507,11 @@ 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