u/Far_Significance334

I recently ran into an interesting verifier compatibility issue while testing an XDP program.

The program loaded successfully on:

• Debian 13 (6.12.63)
• Ubuntu 24.04 with 6.17.0-35-generic

But failed verification on:

• Ubuntu 24.04.4 LTS (6.8.0-124-generic)

The failure was related to pointer arithmetic that newer kernels accepted but 6.8 rejected.

It wasn't a missing helper, kfunc, or feature-gating issue—just different verifier behavior across kernels.

For people shipping eBPF programs in production, have differences in verifier behavior caused more operational pain than missing features? How are you handling kernel compatibility testing today?