From: José Expósito jose.exposito89@gmail.com
[ 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@gmail.com Signed-off-by: Jiri Kosina jkosina@suse.cz Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1f3ea6c93ef44..0fdac91c5f510 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 */