[PATCH 1/2] virtio-crypto: verify src&dst buffer length for sym request

[zhenwei pi]

For symmetric algorithms, the length of ciphertext must be as same
as the plaintext.
The missing verification of the src_len and the dst_len in
virtio_crypto_sym_op_helper() may lead buffer overflow/divulged.

This patch is originally written by Yiming Tao for QEMU-SECURITY,
resend it(a few changes of error message) in qemu-devel.

Fixes: CVE-2023-3180
Fixes: 04b9b37edda("virtio-crypto: add data queue processing handler")
Cc: Gonglei <arei.gonglei@huawei.com>
Cc: Mauro Matteo Cascella <mcascell@redhat.com>
Cc: Yiming Tao <taoym@zju.edu.cn>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
---
 hw/virtio/virtio-crypto.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c
index 44faf5a522..13aec771e1 100644
--- a/hw/virtio/virtio-crypto.c
+++ b/hw/virtio/virtio-crypto.c
@@ -634,6 +634,11 @@ virtio_crypto_sym_op_helper(VirtIODevice *vdev,
         return NULL;
     }
 
+    if (unlikely(src_len != dst_len)) {
+        virtio_error(vdev, "sym request src len is different from dst len");
+        return NULL;
+    }
+
     max_len = (uint64_t)iv_len + aad_len + src_len + dst_len + hash_result_len;
     if (unlikely(max_len > vcrypto->conf.max_size)) {
         virtio_error(vdev, "virtio-crypto too big length");
-- 
2.34.1