MySQL memory usage slowly increasing then crash - what's causing this?
What else is running on the machine?  There seem to be 2 or 3 jumps in memory usage.  MySQL (usually) has one jump or gradual rise.

Nothing looks wrong in my.cnf.  But change innodb_buffer_pool_size to 5G; that will probably keep it from crashing as much.

What OS are you using?  If it has "swappiness", set that to 1, not 0.