In context of USB disconnect, the delaywork trigger and calling appledisplay_bl_get_brightness() and the msgdata was freed. add the checking return value of usb_control_msg() and only update the data while the retval is valid. Reported-by: syzbot+495dab1f175edc9c2f13@xxxxxxxxxxxxxxxxxxxxxxxxx Reported-and-tested-by: syzbot+495dab1f175edc9c2f13@xxxxxxxxxxxxxxxxxxxxxxxxx https://groups.google.com/d/msg/syzkaller-bugs/dRmkh2UYusY/l2a6Mg3FAQAJ Signed-off-by: Phong Tran <tranmanphong@xxxxxxxxx> --- drivers/usb/misc/appledisplay.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/misc/appledisplay.c b/drivers/usb/misc/appledisplay.c index ac92725458b5..3e3dfa5a3954 100644 --- a/drivers/usb/misc/appledisplay.c +++ b/drivers/usb/misc/appledisplay.c @@ -164,7 +164,8 @@ static int appledisplay_bl_get_brightness(struct backlight_device *bd) 0, pdata->msgdata, 2, ACD_USB_TIMEOUT); - brightness = pdata->msgdata[1]; + if (retval >= 0) + brightness = pdata->msgdata[1]; mutex_unlock(&pdata->sysfslock); if (retval < 0) -- 2.20.1
