Applying to a Master degree

No problems at all but my advice would be , when you graduate , apply for the conversion of your permesso di soggiorno from studies to work. You can study as much as you want.

Why? If i want to apply for work permesso i need a job first !

Because the work permesso is better on every way  excample : you want to take a little 3 -4 month brake from university to work you can work as much as you want with the work permit(you can do it too with the study permit but a lot of emplyers dont know it and wont hire you , i have been there 1 million times) , no you dont need a job , you just need the issued diploma and they will give you a new permesso for 1 year to find a job. Like i said the conversion is just my advice , but as far as the second master goes you can do it without any problem.