ACPI / processor: Fix potential NULL pointer dereference in acpi_processor_add()

In acpi_processor_add(), get_cpu_device() may return NULL in some cases
which is then passed to acpi_bind_one() and that will case a NULL
pointer dereference to occur.

Add a check to prevent that from happening.

[rjw: Changelog]
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 157e7389a5ff..e9b01e35ac37 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -393,6 +393,11 @@ static int __cpuinit acpi_processor_add(struct acpi_device *device,
         per_cpu(processors, pr->id) = pr;
 
         dev = get_cpu_device(pr->id);
+        if (!dev) {
+                result = -ENODEV;
+                goto err;
+        }
+
         result = acpi_bind_one(dev, pr->handle);
         if (result)
                 goto err;