CUDA out of memory

[aooating]

my codes are as follows:
with higher.innerloop_ctx(model, model_opt) as (fmodel, diffopt):
for j in range(param_config['inner_steps']):
buff_out = fmodel(buff_imgs)
buff_loss = criterion(.......)
diffopt.step(buff_loss)
After each inner loop, CUDA memory increases until the cache explodes.