tpuproxy: cap VFIO_DEVICE_GET_INFO copy-out size to appArgsz

len(buf) may be larger than appArgsz since it's required to be at least
deviceInfo.SizeBytes().

PiperOrigin-RevId: 916048743

pkg/sentry/devices/tpuproxy/vfio/pci_device_fd.go

@@ -220,7 +220,7 @@ retry:
 	// gVisor is not supposed to change any device information that is
 	// returned from the host since gVisor doesn't own the device.
 	// Passing the device info back to the caller will be just fine.
-	if _, err := t.CopyOutBytes(arg, buf); err != nil {
+	if _, err := t.CopyOutBytes(arg, buf[:min(len(buf), appArgsz)]); err != nil {
 		return 0, err
 	}
 	return ret, nil