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)) {
diff --git a/drivers/media/usb/as102/as102_drv.c b/drivers/media/usb/as102/as102_drv.c
index 6b1d3528a0a7..9a6e554ba9d9 100644
--- a/drivers/media/usb/as102/as102_drv.c
+++ b/drivers/media/usb/as102/as102_drv.c
@@ -322,6 +322,9 @@ int as102_dvb_register(struct as102_dev_t *as102_dev)
 		goto edmxdinit;
 	}
 
+	/* init start / stop stream mutex */
+	mutex_init(&as102_dev->sem);
+
 	/* Attach the frontend */
 	as102_dev->dvb_fe = dvb_attach(as102_attach, as102_dev->name,
 				       &as102_fe_ops,
@@ -344,9 +347,6 @@ int as102_dvb_register(struct as102_dev_t *as102_dev)
 	/* init bus mutex for token locking */
 	mutex_init(&as102_dev->bus_adap.lock);
 
-	/* init start / stop stream mutex */
-	mutex_init(&as102_dev->sem);
-
 	/*
 	 * try to load as102 firmware. If firmware upload failed, we'll be
 	 * able to upload it later.