In a small skillet, melt the butter over medium heat. Add the garlic and cook for about 1 minute. Mix in the flour, and cook for another minute. Whisk in the milk and cook, whisking constantly until thickened, about 3 minutes. Add the cream cheese and Parmesan cheese and whisk until melted.
Meanwhile, bring a large pot of salted water to a boil. Add the linguine and cook until al dente. Reserve 1 cup of cooking water, then drain pasta and return to pot.
Add the sauce and 1/2 cup of the reserved water to the pasta, and toss to combine, adding more cooking water as needed to loosen. Divide among bowls and enjoy.