Managed to be able to step into OpenCL kernels using Ubuntu 12.04 and fglrx driver 13.101. It looks like CodeXL doesn't support Ubuntu 14.04 yet (at least for me), even though the "Requirements"(http://developer.amd.com/tools-and-sdks/opencl-zone/opencl-tools-sdks/codexl/) says otherwise.
According to the call stack in your crash report, this is a known issue caused by the progression of the compiler in the newest AMD Radeon drivers.
This issue will be fixed in the upcoming release of CodeXL (1.5).
If you have access to a driver before 14.4 (e.g., 14.1), you may want to switch to using it until CodeXL 1.5 is released.
Sorry for the inconvenience,