Re: [syzbot] [media?] INFO: trying to register non-static key in as102_dvb_dmx_start_feed

[Edward Adam Davis]

#syz test

diff --git a/drivers/media/dvb-core/dmxdev.c b/drivers/media/dvb-core/dmxdev.c
index 3c8bc75e4d6c..f35c514a420a 100644
--- a/drivers/media/dvb-core/dmxdev.c
+++ b/drivers/media/dvb-core/dmxdev.c
@@ -1053,6 +1053,11 @@ static int dvb_demux_do_ioctl(struct file *file,
 	if (mutex_lock_interruptible(&dmxdev->mutex))
 		return -ERESTARTSYS;
 
+	if (dmxdev->exit) {
+		mutex_unlock(&dmxdev->mutex);
+		return -ENODEV;
+	}
+
 	switch (cmd) {
 	case DMX_START:
 		if (mutex_lock_interruptible(&dmxdevfilter->mutex)) {