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

[ Upstream commit 0a94131d6920916ccb6a357037c535533af08819 ]

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: 1443827 ("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>

diff --git a/drivers/hid/hid-uclogic-params.c b/drivers/hid/hid-uclogic-params.c
index 3c10b858cf74c68993bc610e75fdefaee1d0e78d..3a83e2c39b4fb484c917692b775da2aac0e5872b 100644 (file)
--- a/drivers/hid/hid-uclogic-params.c
+++ b/drivers/hid/hid-uclogic-params.c
@@ -66,7 +66,7 @@ static int uclogic_params_get_str_desc(__u8 **pbuf, struct hid_device *hdev,
                                        __u8 idx, size_t len)
 {
        int rc;
-       struct usb_device *udev = hid_to_usb_dev(hdev);
+       struct usb_device *udev;
        __u8 *buf = NULL;
 
        /* Check arguments */
@@ -75,6 +75,8 @@ static int uclogic_params_get_str_desc(__u8 **pbuf, struct hid_device *hdev,
                goto cleanup;
        }
 
+       udev = hid_to_usb_dev(hdev);
+
        buf = kmalloc(len, GFP_KERNEL);
        if (buf == NULL) {
                rc = -ENOMEM;