From: Oliver Neukum oneukum@suse.com
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 oneukum@suse.com Reported-by: syzbot+0c90fc937c84f97d0aa6@syzkaller.appspotmail.com Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/media/usb/cpia2/cpia2_usb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- 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 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 wake_up_interruptible(&cam->wq_stream); }
+ v4l2_device_put(&cam->v4l2_dev); + LOG("CPiA2 camera disconnected.\n"); }