HID: hid-uclogic-params: Invalid parameter check in uclogic_params_init

The function performs a check on its input parameters, however, the
hdev parameter is used before the check.

Initialize the stack variables after checking the input parameters to
avoid a possible NULL pointer dereference.

Fixes: 9614219e93 ("HID: uclogic: Extract tablet parameter discovery into a module")
Addresses-Coverity-ID: 1443831 ("Null pointer dereference")
Signed-off-by: José Expósito <jose.exposito89@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
José Expósito 2022-01-05 18:29:12 +01:00 committed by Jiri Kosina
parent 13251ce1dd
commit f364c571a5

View File

@ -834,10 +834,10 @@ int uclogic_params_init(struct uclogic_params *params,
struct hid_device *hdev)
{
int rc;
struct usb_device *udev = hid_to_usb_dev(hdev);
__u8 bNumInterfaces = udev->config->desc.bNumInterfaces;
struct usb_interface *iface = to_usb_interface(hdev->dev.parent);
__u8 bInterfaceNumber = iface->cur_altsetting->desc.bInterfaceNumber;
struct usb_device *udev;
__u8 bNumInterfaces;
struct usb_interface *iface;
__u8 bInterfaceNumber;
bool found;
/* The resulting parameters (noop) */
struct uclogic_params p = {0, };
@ -848,6 +848,11 @@ int uclogic_params_init(struct uclogic_params *params,
goto cleanup;
}
udev = hid_to_usb_dev(hdev);
bNumInterfaces = udev->config->desc.bNumInterfaces;
iface = to_usb_interface(hdev->dev.parent);
bInterfaceNumber = iface->cur_altsetting->desc.bInterfaceNumber;
/*
* Set replacement report descriptor if the original matches the
* specified size. Otherwise keep interface unchanged.