Comparing an int to a size, which is unsigned, causes the int to become unsigned, giving the wrong result. kinect_read returns the result of usb_control_msg, which can return a negtive error code. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ int x; expression e,e1; identifier f; @@ *x = f(...); ... when != x = e1 when != if (x < 0 || ...) { ... return ...; } *x < sizeof(e) // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx> --- drivers/media/usb/gspca/kinect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/media/usb/gspca/kinect.c b/drivers/media/usb/gspca/kinect.c index 0cfdf8a..f993f62 100644 --- a/drivers/media/usb/gspca/kinect.c +++ b/drivers/media/usb/gspca/kinect.c @@ -163,7 +163,7 @@ static int send_cmd(struct gspca_dev *gspca_dev, uint16_t cmd, void *cmdbuf, actual_len = kinect_read(udev, ibuf, 0x200); } while (actual_len == 0); gspca_dbg(gspca_dev, D_USBO, "Control reply: %d\n", actual_len); - if (actual_len < sizeof(*rhdr)) { + if (actual_len < (int)sizeof(*rhdr)) { pr_err("send_cmd: Input control transfer failed (%d)\n", actual_len); return actual_len < 0 ? actual_len : -EREMOTEIO;
