[patch] ACPI: fix oops after dock driver fails to initialize

From: Chuck Ebbert
Date: Tue May 08 2007 - 18:40:10 EST


ACPI: fix oops 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@xxxxxxxxxx>

---
drivers/acpi/dock.c | 6 ++++++
1 file changed, 6 insertions(+)

--- 2.6.21-d390.orig/drivers/acpi/dock.c
+++ 2.6.21-d390/drivers/acpi/dock.c
@@ -698,6 +698,7 @@ 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);
@@ -705,6 +706,7 @@ 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);
@@ -713,6 +715,7 @@ 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;
}

@@ -725,6 +728,7 @@ 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;
}
@@ -752,6 +756,7 @@ dock_add_err_unregister:
device_remove_file(&dock_device.dev, &dev_attr_undock);
platform_device_unregister(&dock_device);
kfree(dock_station);
+ dock_station = NULL;
return ret;
}

@@ -785,6 +790,7 @@ static int dock_remove(void)

/* free dock station memory */
kfree(dock_station);
+ dock_station = NULL;
return 0;
}