From: Oliver Neukum Date: Thu, 9 May 2019 08:57:09 +0000 (-0400) Subject: media: cpia2_usb: first wake up, then free in disconnect X-Git-Tag: v5.2.6~14 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=7951663c80a558ac97978e19ba893f9f6d3dec3d;p=users%2Fdwmw2%2Flinux.git media: cpia2_usb: first wake up, then free in disconnect commit eff73de2b1600ad8230692f00bc0ab49b166512a upstream. Kasan reported a use after free in cpia2_usb_disconnect() It first freed everything and then woke up those waiting. The reverse order is correct. Fixes: 6c493f8b28c67 ("[media] cpia2: major overhaul to get it in a working state again") Signed-off-by: Oliver Neukum Reported-by: syzbot+0c90fc937c84f97d0aa6@syzkaller.appspotmail.com Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/media/usb/cpia2/cpia2_usb.c b/drivers/media/usb/cpia2/cpia2_usb.c index b2268981c963c..17468f7d78ed2 100644 --- a/drivers/media/usb/cpia2/cpia2_usb.c +++ b/drivers/media/usb/cpia2/cpia2_usb.c @@ -893,7 +893,6 @@ static void cpia2_usb_disconnect(struct usb_interface *intf) cpia2_unregister_camera(cam); v4l2_device_disconnect(&cam->v4l2_dev); mutex_unlock(&cam->v4l2_lock); - v4l2_device_put(&cam->v4l2_dev); if(cam->buffers) { DBG("Wakeup waiting processes\n"); @@ -902,6 +901,8 @@ static void cpia2_usb_disconnect(struct usb_interface *intf) wake_up_interruptible(&cam->wq_stream); } + v4l2_device_put(&cam->v4l2_dev); + LOG("CPiA2 camera disconnected.\n"); }