From: José Expósito jose.exposito89@gmail.com
[ Upstream commit f364c571a5c77e96de2d32062ff019d6b8d2e2bc ]
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: 1443831 ("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 | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/hid/hid-uclogic-params.c b/drivers/hid/hid-uclogic-params.c index dd05bed4ca53a..851ab8e24f9d7 100644 --- a/drivers/hid/hid-uclogic-params.c +++ b/drivers/hid/hid-uclogic-params.c @@ -832,10 +832,10 @@ 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, }; @@ -846,6 +846,11 @@ 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.