0007641: Kernel hangs when accessing ttyS0

I have several machines running CentOS 6.5 and CentOS 7. Most of them are in production, but I'm using my pre-prod ones to setup network equipment. I recently noticed that using kernel 3.6.10 to 3.6.14 on both CentOS 6.5 and CentOS 7 would result in the machine crashing (hanging) when I would try to access the serial port.<br /> <br /> All of the 2.6.x kernels aren't reproducing the issue.