From: Kirill Tkhai Date: Thu, 17 Apr 2014 20:47:04 +0000 (-0300) Subject: [media] s2255: Do not free fw_data until timer handler has actually stopped using it X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9f6be2bc403c0cea8d7b72cd5d42bd1a22b369ed;p=linux-beck.git [media] s2255: Do not free fw_data until timer handler has actually stopped using it Function del_timer() does not guarantee that timer was really deleted. If the timer handler is beeing executed at the moment, the function does nothing. So, we have a race between del_timer() and kfree(), and it's possible to use already freed memory in the handler. Signed-off-by: Kirill Tkhai Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/usb/s2255/s2255drv.c b/drivers/media/usb/s2255/s2255drv.c index e019dd63ed42..185be72cab14 100644 --- a/drivers/media/usb/s2255/s2255drv.c +++ b/drivers/media/usb/s2255/s2255drv.c @@ -1521,7 +1521,7 @@ static void s2255_destroy(struct s2255_dev *dev) /* board shutdown stops the read pipe if it is running */ s2255_board_shutdown(dev); /* make sure firmware still not trying to load */ - del_timer(&dev->timer); /* only started in .probe and .open */ + del_timer_sync(&dev->timer); /* only started in .probe and .open */ if (dev->fw_data->fw_urb) { usb_kill_urb(dev->fw_data->fw_urb); usb_free_urb(dev->fw_data->fw_urb); @@ -2351,7 +2351,7 @@ errorREQFW: errorFWDATA2: usb_free_urb(dev->fw_data->fw_urb); errorFWURB: - del_timer(&dev->timer); + del_timer_sync(&dev->timer); errorEP: usb_put_dev(dev->udev); errorUDEV: