Due to https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=144593
That bug is very similar to one I filed that was closed because dmesg showed the grep segfault was due to the NVidia drivers.
I'm willing to bet that should the reporter disable the nvidia driver, his grep would work perfectly - even with the nvidia modules still in / etc/udev/devices.
I'll look for my bug number for you to refer to.
