On several servers running CentOS 6.7 the free command and top command show incorrect used and free swap numbers. Is this a bug?

All applications on these servers are running fine.

Specifics:
CentOS release 6.7 (Final)
Kernel 2.6.32-573.3.1.el6.x86_64
12GB RAM

# free -m
total used free shared buffers cached
Mem: 11902 8218 3683 2 107 1111
-/+ buffers/cache: 7000 4902
Swap: 2047 1759218600 43853


# top -M

top - 15:17:15 up 3:08, 1 user, load average: 10.59, 9.11, 7.98
Tasks: 342 total, 1 running, 341 sleeping, 0 stopped, 0 zombie
Cpu(s): 59.2%us, 0.2%sy, 0.0%ni, 38.0%id, 2.6%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 11.623G total, 8231.625M used, 3670.742M free, 107.543M buffers
Swap: 2047.992M total, 17592186044375.174G used, 42.826G free, 1114.492M cached

Compare with

hah, certainly looks like a bug to me. Either that or you've discovered a hole in space time, in which you can dump 1.7 PB of data (or 17 ZB if you look at top) into a 2 GB partition and still have 43 GB free!