Those kernel modules (`ashmem` and `hwbinder`) are standard when building the Linux kernel for Android and they are already part of the upstream Linux kernel tree [1][2]. Because this solution uses containers (which share the same kernel with the host OS), these additional modules are needed.

From the ReDroid kernel modules readme:

>Custom Kernel

>If use custom kernel (5.0+), you can enable binderfs and ashmem configs; So the kernel modules in this repo are not needed any more.

https://github.com/remote-android/redroid-modules#custom-ker...

More info here on Android-specific kernel modules here:

https://elinux.org/Android_Kernel_Features#List_of_kernel_fe...

[1] ashmem

https://github.com/torvalds/linux/blob/master/drivers/stagin...

[2] hwbinder

https://github.com/torvalds/linux/tree/master/drivers/androi...