[ 14/23] ACPI / memhotplug: Fix a stale pointer in error path

Greg Kroah-Hartman
2013-08-02T10:26:14Z

From: Toshi Kani <toshi.kani@hp.com>

commit d19f503e22316a84c39bc19445e0e4fdd49b3532 upstream.

device->driver_data needs to be cleared when releasing its data,
mem_device, in an error path of acpi_memory_device_add().

The function evaluates the _CRS of memory device objects, and fails
when it gets an unexpected resource or cannot allocate memory. A
kernel crash or data corruption may occur when the kernel accesses
the stale pointer.

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/acpi/acpi_memhotplug.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -421,6 +421,7 @@ static int acpi_memory_device_add(struct
/* Get the range from the _CRS */
result = acpi_memory_get_device_resources(mem_device);
if (result) {
+ device->driver_data = NULL;
kfree(mem_device);
return result;
}