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

    * Igor Mammedov <imammedo@redhat.com> 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


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