Re: [syzbot] [kernel?] general protection fault in timers_dead_cpu

[Borislav Petkov]

On Mon, Aug 17, 2026 at 04:55:53PM -0700, Borislav Petkov wrote:
> On Mon, Aug 17, 2026 at 11:14:35PM +0200, Thomas Gleixner wrote:
> >  timers_dead_cpu()
> >    migrate timer to CPU0
> >    
> >    // Migrates the MCE timer of CPU1, which is a bug in itself
> 
> Stupid question: can we prevent this?
> 
> As in, this timer is not migratable, do not migrate it.
> 
> But then what do you do with a timer which is not migratable and its CPU goes
> offline?
> 
> Perhaps cancel it...
> 
> It won't matter in the MCE case, that's for sure.
> 
> Anyway, just some musings from reading this...

Hmm, the down path does timer_delete_sync() so I guess I'm missing an aspect
here about the timer migration.

-- 
Regards/Gruss,
    Boris.

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