I’m not sure to understand your question correctly.
If you would like to store the output of self.bn1 to use it as a skip connection, you can just use another variable name:
    def forward(self, x):
          out = self.conv1(x)
          bn_out = self.bn1(out)
          out = self.maxpool(bn_out)
          return F.log_softmax(self.linear(out))