Are the waves on survival completely endless?

Solution 1:

As I said in my comment, the Call of Duty wikia says that the waves are endless. I also thought that would be the case because that is normally what "survival mode" means.

Survival Mode - The Call of Duty Wiki

I was going to leave only a comment, but then I tried to search for the hiding spot you mentioned and I found some videos of people getting to much higher waves, like this one ending on wave 225 and calling it a world record:

While this doesn't prove that there isn't a secret ending at some point, it probably does prove that you would get bored and want to quit long before you reach it.

Also, in theory the waves will stop increasing once the number of waves reaches or exceeds the largest integer supported by the system's processor. This would probably require more than a year of constant gameplay even on a 32-bit system, but it's an interesting note to add.