From: Julien Brunel <brunel@xxxxxxx> In case of error, the function backlight_device_register returns an ERR pointer, but never returns a NULL pointer. So a NULL test that may come after a call to this function should be strengthened by an IS_ERR test. The semantic match that finds this problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @match_bad_null_test@ expression x, E; statement S1,S2; @@ x = backlight_device_register(...) ... when != x = E * if (x != NULL) S1 else S2 // </smpl> Signed-off-by: Julien Brunel <brunel@xxxxxxx> Signed-off-by: Julia Lawall <julia@xxxxxxx> --- drivers/usb/misc/appledisplay.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -u -p a/drivers/usb/misc/appledisplay.c b/drivers/usb/misc/appledisplay.c --- a/drivers/usb/misc/appledisplay.c +++ b/drivers/usb/misc/appledisplay.c @@ -314,7 +314,7 @@ error: pdata->urbdata, pdata->urb->transfer_dma); usb_free_urb(pdata->urb); } - if (pdata->bd) + if (pdata->bd && !IS_ERR(pdata->bd)) backlight_device_unregister(pdata->bd); kfree(pdata->msgdata); } -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html