From: José Expósito <jose.exposito89@xxxxxxxxx>
[ Upstream commit ff6b548afe4d9d1ff3a0f6ef79e8cbca25d8f905 ]
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: 9614219e9310e ("HID: uclogic: Extract tablet parameter discovery into a module")
Addresses-Coverity-ID: 1443804 ("Null pointer dereference")
Signed-off-by: José Expósito <jose.exposito89@xxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/hid/hid-uclogic-params.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/hid/hid-uclogic-params.c b/drivers/hid/hid-uclogic-params.c
index a751c9a49360f..df12178a80da5 100644
--- a/drivers/hid/hid-uclogic-params.c
+++ b/drivers/hid/hid-uclogic-params.c
@@ -707,9 +707,9 @@ static int uclogic_params_huion_init(struct uclogic_params *params,
struct hid_device *hdev)
{
int rc;
- struct usb_device *udev = hid_to_usb_dev(hdev);
- struct usb_interface *iface = to_usb_interface(hdev->dev.parent);
- __u8 bInterfaceNumber = iface->cur_altsetting->desc.bInterfaceNumber;
+ struct usb_device *udev;
+ struct usb_interface *iface;
+ __u8 bInterfaceNumber;
bool found;
/* The resulting parameters (noop) */
struct uclogic_params p = {0, };
@@ -723,6 +723,10 @@ static int uclogic_params_huion_init(struct uclogic_params *params,
goto cleanup;
}
+ udev = hid_to_usb_dev(hdev);
+ iface = to_usb_interface(hdev->dev.parent);
+ bInterfaceNumber = iface->cur_altsetting->desc.bInterfaceNumber;
+
/* If it's not a pen interface */
if (bInterfaceNumber != 0) {
/* TODO: Consider marking the interface invalid */
--
2.34.1
