Re: [PATCH v3 4/5] x86: fix memory corruption in acpi_unmap_lsapic()

[Ingo Molnar]

* Igor Mammedov <imammedo@xxxxxxxxxx> wrote:

> if during CPU hotplug master CPU failed to wake up AP
> it set percpu x86_cpu_to_apicid to BAD_APICID=0xFFFF for AP.
> 
> However following attempt to unplug that CPU will lead to
> out of bound write access to __apicid_to_node[] which is
> 32768 items long on x86_64 kernel.
> 
> So drop setting x86_cpu_to_apicid to BAD_APICID in do_boot_cpu()
> and allow acpi_processor_remove()->acpi_unmap_lsapic() cleanly
> remove CPU.

Same suggestion as for the other fix patch: the fix should precede the 
patch that exposes it.

Thanks,

	Ingo
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/