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 67e123f ("Delete
 unnecessary checks")]

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index 936ad7770ec3a5eb4849f93bd3e050989d674833..3512d833cc24d60a7b4d235bd040e4d6f131eb67 100644 (file)
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -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;