[PATCH next] HID: hid-goodix: Fix a signedness bug in goodix_hid_get_raw_report()

[Dan Carpenter]

GOODIX_HID_PKG_LEN_SIZE defined as sizeof(u16) (type size_t).  If the
goodix_hid_check_ack_status() function times out and return -EINVAL then,
because of type promotion, the negative error code is treated as a high
positive value which is success.

Fix this by adding an explicit check for negative error codes.

Fixes: 75e16c8ce283 ("HID: hid-goodix: Add Goodix HID-over-SPI driver")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
 drivers/hid/hid-goodix-spi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-goodix-spi.c b/drivers/hid/hid-goodix-spi.c
index 5103bf0aada4..59415f95c675 100644
--- a/drivers/hid/hid-goodix-spi.c
+++ b/drivers/hid/hid-goodix-spi.c
@@ -435,7 +435,8 @@ static int goodix_hid_get_raw_report(struct hid_device *hid,
 
 	/* Step2: check response data status */
 	response_data_len = goodix_hid_check_ack_status(ts);
-	if (response_data_len <= GOODIX_HID_PKG_LEN_SIZE)
+	if (response_data_len < 0 ||
+	    response_data_len <= GOODIX_HID_PKG_LEN_SIZE)
 		return -EINVAL;
 
 	len = min(len, response_data_len - GOODIX_HID_PKG_LEN_SIZE);
-- 
2.43.0