(In reply to Jiri Slaby from comment #10) > smp_call_function_single+0xea -- what kernel flavor+version exactly is this > with? Nevermind, it's likely 5.12.0-1. And the stack trace boils up to toggle_allocation_gate. That is kfence and kfence is new in 5.12. Does adding kfence.sample_interval=0 to kernel parameter workaround the issue?