Re: [BUG] Random hard lockup with userspace %ip on 7.0-rc5

Borislav Petkov
2026-04-01T16:35:14Z

On Wed, Apr 01, 2026 at 05:01:00PM +0200, Thomas Gleixner wrote:
> Now that you have a reproducer, can you verify that the machine really
> locks up hard? Disable the NMI watchdog either via the kernel command
> line 'nmi_watchdog=0' or via echo 0 >/proc/sys/kernel/nmi_watchdog.
>
> If that works and the machine stays usable then the watchdog is
> hallucinating.

Yeah, I was able to reproduce here. I am able to Ctrl-C the reproducer so the
machine is responsive after that.

We'll enable tracing and take it from there.

Calvin, thanks for the report - you don't really have to update your BIOS
- I can reproduce with the latest.

And thanks for the reproducer.

--
Regards/Gruss,
Boris.