ACPI: dock: fix opps after dock driver fails to initialize

The driver tests the dock_station pointer for nonnull
to check whether it has initialized properly. But in
some cases dock_station will be non-null after being
freed when driver init fails. Fix by zeroing the
pointer after freeing.

Signed-off-by: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index 9ddc3f189bb7..f66f4f7767ac 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -715,6 +715,7 @@ static int dock_add(acpi_handle handle)
         if (ret) {
                 printk(KERN_ERR PREFIX "Error %d registering dock device\n", ret);
                 kfree(dock_station);
+                dock_station = NULL;
                 return ret;
         }
         ret = device_create_file(&dock_device.dev, &dev_attr_docked);
@@ -722,6 +723,7 @@ static int dock_add(acpi_handle handle)
                 printk("Error %d adding sysfs file\n", ret);
                 platform_device_unregister(&dock_device);
                 kfree(dock_station);
+                dock_station = NULL;
                 return ret;
         }
         ret = device_create_file(&dock_device.dev, &dev_attr_undock);
@@ -730,6 +732,7 @@ static int dock_add(acpi_handle handle)
                 device_remove_file(&dock_device.dev, &dev_attr_docked);
                 platform_device_unregister(&dock_device);
                 kfree(dock_station);
+                dock_station = NULL;
                 return ret;
         }
         ret = device_create_file(&dock_device.dev, &dev_attr_uid);
@@ -739,6 +742,7 @@ static int dock_add(acpi_handle handle)
                 device_remove_file(&dock_device.dev, &dev_attr_undock);
                 platform_device_unregister(&dock_device);
                 kfree(dock_station);
+                dock_station = NULL;
                 return ret;
         }
 
@@ -751,6 +755,7 @@ static int dock_add(acpi_handle handle)
         dd = alloc_dock_dependent_device(handle);
         if (!dd) {
                 kfree(dock_station);
+                dock_station = NULL;
                 ret = -ENOMEM;
                 goto dock_add_err_unregister;
         }
@@ -779,6 +784,7 @@ dock_add_err_unregister:
         device_remove_file(&dock_device.dev, &dev_attr_uid);
         platform_device_unregister(&dock_device);
         kfree(dock_station);
+        dock_station = NULL;
         return ret;
 }
 
@@ -813,6 +819,7 @@ static int dock_remove(void)
 
         /* free dock station memory */
         kfree(dock_station);
+        dock_station = NULL;
         return 0;
 }