[PATCH 5.4 111/320] HID: hid-uclogic-params: Invalid parameter check in uclogic_params_frame_init_v1_buttonpad

Greg Kroah-Hartman
2022-01-24T19:32:41Z

From: José Expósito <jose.exposito89@gmail.com>

[ Upstream commit aa320fdbbbb482c19100f51461bd0069753ce3d7 ]

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

Initialize the udev variable after the sanity check to avoid a
possible NULL pointer dereference.

Fixes: 9614219e9310e ("HID: uclogic: Extract tablet parameter discovery into a module")
Addresses-Coverity-ID: 1443763 ("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 | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-uclogic-params.c b/drivers/hid/hid-uclogic-params.c
index 0fdac91c5f510..191aba9f6b497 100644
--- a/drivers/hid/hid-uclogic-params.c
+++ b/drivers/hid/hid-uclogic-params.c
@@ -451,7 +451,7 @@ static int uclogic_params_frame_init_v1_buttonpad(
{
int rc;
bool found = false;
- struct usb_device *usb_dev = hid_to_usb_dev(hdev);
+ struct usb_device *usb_dev;
char *str_buf = NULL;
const size_t str_len = 16;

@@ -461,6 +461,8 @@ static int uclogic_params_frame_init_v1_buttonpad(
goto cleanup;
}

+ usb_dev = hid_to_usb_dev(hdev);
+
/*
* Enable generic button mode
*/
--
2.34.1