As requested, I've peeled back the C-state limitation and SRSO workaround to isolate the issue.
Current boot parameters: retbleed=off nmi_watchdog=1 Mitigation status after boot: /sys/devices/system/cpu/vulnerabilities/retbleed: Vulnerable /sys/devices/system/cpu/vulnerabilities/spec_rstack_overflow: Mitigation: Safe RET C-states available: POLL, C1, C2, C3 (all deep states enabled, no processor.max_cstate restriction) Kernel: 7.0.0-28-generic (Ubuntu 26.04 LTS) This means SRSO mitigation (srso_return_thunk/Safe RET) is active, deep C-states are enabled, and only retbleed mitigation is disabled. I will monitor for 3-4 days and report back. If this remains stable, it confirms the issue is purely in the retbleed return thunk and not SRSO's implementation, even though earlier crashes showed srso_safe_ret in the backtrace (likely because srso_return_thunk is used as the active return thunk when retbleed is enabled). -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2160457 Title: Kernel panic in srso_safe_ret / kick_ilb during sched_tick on AMD Ryzen 7 4800U (Zen2) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2160457/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
