In the Linux kernel, the following vulnerability has been resolved:
crypto: virtio - Add spinlock protection with virtqueue notification
When VM boots with one virtio-crypto PCI device and builtin backend,
run openssl benchmark command with multiple processes, such as
openssl speed -evp aes-128-cbc -engine afalg -seconds 10 -multi 32
openssl processes will hangup and there is error reported like this:
virtio_crypto virtio0: dataq.0:id 3 is not a head!
It seems that the data virtqueue need protection when it is handled
for virtio done notification. If the spinlock protection is added
in virtcrypto_done_task(), openssl benchmark with multiple processes
works well.