some question about the white box attack

[yuese1234]

Sorry to bother you again.
When I run your white-box attack code for LLaVA, the gradient is None. The specific problem is:
adv_noise.data = (adv_noise.data - alpha * adv_noise.grad.detach().sign()).clamp(0, 1)
AttributeError: 'NoneType' object has no attribute 'detach'. Can you give me some help?