From: Jason Wang jasowang@redhat.com
commit 228432551bd8783211e494ab35f42a4344580502 upstream.
Current virtio-rng does a entropy request before DRIVER_OK, this violates the spec:
virtio spec requires that all drivers set DRIVER_OK before using devices.
Further, kernel will ignore the interrupt after commit 8b4ec69d7e09 ("virtio: harden vring IRQ").
Fixing this by making device ready before the request.
Cc: stable@vger.kernel.org Fixes: 8b4ec69d7e09 ("virtio: harden vring IRQ") Fixes: f7f510ec1957 ("virtio: An entropy device, as suggested by hpa.") Reported-and-tested-by: syzbot+5b59d6d459306a556f54@syzkaller.appspotmail.com Signed-off-by: Jason Wang jasowang@redhat.com Message-Id: 20220608061422.38437-1-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Reviewed-by: Laurent Vivier lvivier@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/hw_random/virtio-rng.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -159,6 +159,8 @@ static int probe_common(struct virtio_de goto err_find; }
+ virtio_device_ready(vdev); + /* we always have a pending entropy request */ request_entropy(vi);