Ask HN: I work for one company, but write code for another. Could this be bad?

Hi all,

I'm employed by company A, at which I write software for company A. This is a straight-forward situation.

Company A created a second legal entity, company B. Company B started out as a separate company that company A would sell software under, for licensing reasons that are beyond me.

Recently though, I've been tasked with writing software specifically for company B. As in, I am now managing a team of developers who work for company B, and are writing software for company B, that B will sell. It is meant to be completely separate from A, legally. Now, whether technically it is or not, I do not know - I'm just part of this larger plan.

I'm the only employee at company A working within this cross-company configuration. I'm wondering if there's anything I should be concerned about, or if I should bring anything up with my bosses about this. If so, what should I be asking for? I kind of feel like I'm being overused, but don't really know how to go about handling it.