virtio: reject shm region if length is zero

Prevent usage of shared memory regions where the length is zero,
as such configurations are not valid and may lead to unexpected behavior.

Signed-off-by: Sami Uddin <sami.md.ko@gmail.com>
Message-Id: <20250511222153.2332-1-sami.md.ko@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
index 169c7d3..b3e1d30 100644 (file)
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -329,6 +329,8 @@ static inline
 bool virtio_get_shm_region(struct virtio_device *vdev,
                           struct virtio_shm_region *region, u8 id)
 {
+       if (!region->len)
+               return false;
        if (!vdev->config->get_shm_region)
                return false;
        return vdev->config->get_shm_region(vdev, region, id);