From 0b8a71a8bd2129ca9cc115195fd9630564765772 Mon Sep 17 00:00:00 2001 From: Oliver Neukum Date: Thu, 9 May 2019 04:57:09 -0400 Subject: [PATCH] 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 --- drivers/media/usb/cpia2/cpia2_usb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/cpia2/cpia2_usb.c b/drivers/media/usb/cpia2/cpia2_usb.c index e9100a235831..21e5454d260a 100644 --- a/drivers/media/usb/cpia2/cpia2_usb.c +++ b/drivers/media/usb/cpia2/cpia2_usb.c @@ -909,7 +909,6 @@ 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"); @@ -921,6 +920,8 @@ static void cpia2_usb_disconnect(struct usb_interface *intf) DBG("Releasing interface\n"); usb_driver_release_interface(&cpia2_driver, intf); + v4l2_device_put(&cam->v4l2_dev); + LOG("CPiA2 camera disconnected.\n"); } -- 2.20.1