Baby sleeping with arm dangling out of crib

My son is 7 months. The last few weeks he’s really been rolling all over the crib to go to sleep and sometimes he ends up against the side of it and falls asleep and his arm will dangle out. It’s not stuck, he could easily lift it and pull it in but he just doesn’t.

I’ve tried fixing it but it just falls out minutes later and I don’t wanna move his whole body and wake him if I don’t have to. I’m worried about it falling asleep/hurting him.

Is it a big deal for their arms to hang out? He sleeps comfortably like this lol