vduse: Disallow injecting interrupt before DRIVER_OK is set

The interrupt callback should not be triggered before DRIVER_OK
is set. Otherwise, it might break the virtio device driver.
So let's add a check to avoid the unexpected behavior.

Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace")
Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Link: https://lore.kernel.org/r/20210923075722.98-1-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 26e3d90..cefb301 100644 (file)
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -966,6 +966,10 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
                break;
        }
        case VDUSE_DEV_INJECT_CONFIG_IRQ:
+               ret = -EINVAL;
+               if (!(dev->status & VIRTIO_CONFIG_S_DRIVER_OK))
+                       break;
+
                ret = 0;
                queue_work(vduse_irq_wq, &dev->inject);
                break;
@@ -1045,6 +1049,10 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
        case VDUSE_VQ_INJECT_IRQ: {
                u32 index;
 
+               ret = -EINVAL;
+               if (!(dev->status & VIRTIO_CONFIG_S_DRIVER_OK))
+                       break;
+
                ret = -EFAULT;
                if (get_user(index, (u32 __user *)argp))
                        break;