Not a lawyer, but patent law refers to distribution too. It shouldn't matter if it's free or has a price if they can say you're distributing it to Brazilian users.

Distributing something for free doesn't mean you don't have patent obligations if you do it in the country that patent is valid in. On top of that, many corporations do sell their distribution of Linux.

Plenty of open source software avoids using patents even though it’s free. Selling doesn’t factor into it.

Both Ubuntu and RedHad sell a product, as do few other

Nope. Distribution is what matters.