Which kernel versions does the udev exploit work?
I'm actually not sure that the kernel version matters for this exploit. It was a bug that was patched in the platform_system_core repository, which I think comprises libraries and system files that live on in the /system directory (the README says as much). The patch was committed on July 19, 2010 (in the Froyo branch, anyway).

I'd wager that any kernel with a build date later than that also has the updated system files, so the system wouldn't be vulnerable. uname -a would tell you the build date of a given device's kernel, but beyond that I don't know that you could really line it up with a specific kernel version, especially on devices from different manufacturers/carriers/etc.