releases/3.4.56/acpi-memhotplug-fix-a-stale-pointer-in-error-path.patch

   1 From d19f503e22316a84c39bc19445e0e4fdd49b3532 Mon Sep 17 00:00:00 2001
   2 From: Toshi Kani <toshi.kani@hp.com>
   3 Date: Wed, 10 Jul 2013 10:47:13 -0600
   4 Subject: ACPI / memhotplug: Fix a stale pointer in error path
   5
   6 From: Toshi Kani <toshi.kani@hp.com>
   7
   8 commit d19f503e22316a84c39bc19445e0e4fdd49b3532 upstream.
   9
  10 device->driver_data needs to be cleared when releasing its data,
  11 mem_device, in an error path of acpi_memory_device_add().
  12
  13 The function evaluates the _CRS of memory device objects, and fails
  14 when it gets an unexpected resource or cannot allocate memory.  A
  15 kernel crash or data corruption may occur when the kernel accesses
  16 the stale pointer.
  17
  18 Signed-off-by: Toshi Kani <toshi.kani@hp.com>
  19 Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
  20 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  22
  23 ---
  24  drivers/acpi/acpi_memhotplug.c |    1 +
  25  1 file changed, 1 insertion(+)
  26
  27 --- a/drivers/acpi/acpi_memhotplug.c
  28 +++ b/drivers/acpi/acpi_memhotplug.c
  29 @@ -421,6 +421,7 @@ static int acpi_memory_device_add(struct
  30         /* Get the range from the _CRS */
  31         result = acpi_memory_get_device_resources(mem_device);
  32         if (result) {
  33 +               device->driver_data = NULL;
  34                 kfree(mem_device);
  35                 return result;
  36         }