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Commit d9f2d203 authored by Jason Gerecke's avatar Jason Gerecke Committed by Jiri Kosina
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HID: wacom: Properly free inputs if 'wacom_allocate_inputs' fails 



The 'wacom_allocate_inputs' function tries to allocate three input devices: one
each for the pen, touch, and pad. The pointers that are returned by the
'wacom_allocate_input' calls are temporarily stored to local variables where
they are checked to ensure they're non-null before storing them in the
'wacom_wac' structure. If an allocation fails,  the 'wacom_free_inputs'
function is called to reclaim the memory. Unfortunately, 'wacom_free_inputs' is
called prior to the pointers being copied, so it is not actually able to free
anything.

This patch has the calls to 'wacom_allocate_input' store the pointer directly
in the 'wacom_wac' structure where they can be freed. Also, it replaces the
call to 'wacom_free_inputs' with the (more general) 'wacom_clean_inputs' and
removes the no-longer-used function.

[jkosina@suse.com: modify to resolve conflict with 67e123ff ("Delete
 unnecessary checks")]

Signed-off-by: default avatarJason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.com>
parent 57f7e160

drivers/hid/wacom_sys.c

+18 −34
Original line number Diff line number Diff line
@@ -1145,40 +1145,6 @@ static struct input_dev *wacom_allocate_input(struct wacom *wacom) 
	return input_dev;

}



static void wacom_free_inputs(struct wacom *wacom)

{

	struct wacom_wac *wacom_wac = &(wacom->wacom_wac);



	input_free_device(wacom_wac->pen_input);

	input_free_device(wacom_wac->touch_input);

	input_free_device(wacom_wac->pad_input);

	wacom_wac->pen_input = NULL;

	wacom_wac->touch_input = NULL;

	wacom_wac->pad_input = NULL;

}



static int wacom_allocate_inputs(struct wacom *wacom)

{

	struct input_dev *pen_input_dev, *touch_input_dev, *pad_input_dev;

	struct wacom_wac *wacom_wac = &(wacom->wacom_wac);



	pen_input_dev = wacom_allocate_input(wacom);

	touch_input_dev = wacom_allocate_input(wacom);

	pad_input_dev = wacom_allocate_input(wacom);

	if (!pen_input_dev || !touch_input_dev || !pad_input_dev) {

		wacom_free_inputs(wacom);

		return -ENOMEM;

	}



	wacom_wac->pen_input = pen_input_dev;

	wacom_wac->touch_input = touch_input_dev;

	wacom_wac->touch_input->name = wacom_wac->touch_name;

	wacom_wac->pad_input = pad_input_dev;

	wacom_wac->pad_input->name = wacom_wac->pad_name;



	return 0;

}



static void wacom_clean_inputs(struct wacom *wacom)

{

	if (wacom->wacom_wac.pen_input) {
@@ -1205,6 +1171,24 @@ static void wacom_clean_inputs(struct wacom *wacom) 
	wacom_destroy_leds(wacom);

}



static int wacom_allocate_inputs(struct wacom *wacom)

{

	struct wacom_wac *wacom_wac = &(wacom->wacom_wac);



	wacom_wac->pen_input = wacom_allocate_input(wacom);

	wacom_wac->touch_input = wacom_allocate_input(wacom);

	wacom_wac->pad_input = wacom_allocate_input(wacom);

	if (!wacom_wac->pen_input || !wacom_wac->touch_input || !wacom_wac->pad_input) {

		wacom_clean_inputs(wacom);

		return -ENOMEM;

	}



	wacom_wac->touch_input->name = wacom_wac->touch_name;

	wacom_wac->pad_input->name = wacom_wac->pad_name;



	return 0;

}



static int wacom_register_inputs(struct wacom *wacom)

{

	struct input_dev *pen_input_dev, *touch_input_dev, *pad_input_dev;