From: Oliver Neukum Date: Wed, 6 Nov 2019 12:49:01 +0000 (+0100) Subject: appledisplay: fix error handling in the scheduled work X-Git-Tag: v5.5-rc1~137^2~40 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=91feb01596e5efc0cc922cc73f5583114dccf4d2;p=linux.git appledisplay: fix error handling in the scheduled work The work item can operate on 1. stale memory left over from the last transfer the actual length of the data transfered needs to be checked 2. memory already freed the error handling in appledisplay_probe() needs to cancel the work in that case Reported-and-tested-by: syzbot+495dab1f175edc9c2f13@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum Cc: stable Link: https://lore.kernel.org/r/20191106124902.7765-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/misc/appledisplay.c b/drivers/usb/misc/appledisplay.c index ac92725458b5..ba1eaabc7796 100644 --- a/drivers/usb/misc/appledisplay.c +++ b/drivers/usb/misc/appledisplay.c @@ -164,7 +164,12 @@ static int appledisplay_bl_get_brightness(struct backlight_device *bd) 0, pdata->msgdata, 2, ACD_USB_TIMEOUT); - brightness = pdata->msgdata[1]; + if (retval < 2) { + if (retval >= 0) + retval = -EMSGSIZE; + } else { + brightness = pdata->msgdata[1]; + } mutex_unlock(&pdata->sysfslock); if (retval < 0) @@ -299,6 +304,7 @@ static int appledisplay_probe(struct usb_interface *iface, if (pdata) { if (pdata->urb) { usb_kill_urb(pdata->urb); + cancel_delayed_work_sync(&pdata->work); if (pdata->urbdata) usb_free_coherent(pdata->udev, ACD_URB_BUFFER_LEN, pdata->urbdata, pdata->urb->transfer_dma);