Might have/Might has when 'have' = 'possession'

[DmitryL]

Hi!
I'm aware of the modal character of 'might' verb and that it should be used with 'have' instead of 'has'. But shouldn't I place the 'has' form when I use 'have' in 'possession' meaning?
For example: ' I want to be his friend in spite of all the downsides he might has (might have?)'.

Thank you in advance,

Sincerely,

Dmitry

[Josef]

'Modal auxiliary verbs may sound difficult but in fact they're easy. They are invariable (no conjugation). And the main verb is always the "bare infinitive" (the infinitive without "to").'
from: http://www.englishclub.com/grammar/verbs-modals.htm

I want to be his friend in spite of all the downsides he might have.