contrib/vhost-user-blk: fix get_config() information leak

Refuse get_config() in excess of sizeof(struct virtio_blk_config).

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20201027173528.213464-6-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/contrib/vhost-user-blk/vhost-user-blk.c b/contrib/vhost-user-blk/vhost-user-blk.c
index 25eccd02b51103bab7267fd337a7ea590ed231de..caad88637e9a7788322fae548c794bb4f39f6e74 100644 (file)
--- a/contrib/vhost-user-blk/vhost-user-blk.c
+++ b/contrib/vhost-user-blk/vhost-user-blk.c
@@ -404,6 +404,8 @@ vub_get_config(VuDev *vu_dev, uint8_t *config, uint32_t len)
     VugDev *gdev;
     VubDev *vdev_blk;
 
+    g_return_val_if_fail(len <= sizeof(struct virtio_blk_config), -1);
+
     gdev = container_of(vu_dev, VugDev, parent);
     vdev_blk = container_of(gdev, VubDev, parent);
     memcpy(config, &vdev_blk->blkcfg, len);