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. Signed-off-by: Igor Mammedov <imammedo@xxxxxxxxxx> --- arch/x86/kernel/smpboot.c | 2 -- 1 files changed, 0 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 6124f15..2988f69 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -859,8 +859,6 @@ static int do_boot_cpu(int apicid, int cpu, struct task_struct *idle) /* was set by cpu_init() */ cpumask_clear_cpu(cpu, cpu_initialized_mask); - - per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID; } /* mark "stuck" area as not stuck */ -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
