The crashdump is inconclusive, but your syslog has a lot of errors about bad blocks on a few partitions. You may wanna run a Disk Check
(with both options selected). If you see a good number of errors in it, then it means your drive may be going bad. You'll want to back up your data then run self test and basic tests on Seatools
just to be sure. It is best to backup data before the testing because the testing can stress the drive and if the drive is already dying it may make it worse.