If you are referring to upsampling using http://pytorch.org/docs/nn.html#upsamplingbilinear2d 152 then you can upsample by a non-int scale_factor by directly providing the output size. For example:
import torch
import torch.nn as nn
from torch.autograd import Variable


inp = Variable(torch.randn(10, 3, 24, 24))
m = nn.UpsamplingBilinear2d(size=(55, 55))
out = m(inp)
print(out.size())