Merging upstream version 4.19.289.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 35 insertions, 3 deletions

diff --git a/drivers/media/dvb-core/dvb_net.c b/drivers/media/dvb-core/dvb_net.c
index 3f154755b..6c44526bb 100644
--- a/drivers/media/dvb-core/dvb_net.c
+++ b/drivers/media/dvb-core/dvb_net.c
@@ -1575,15 +1575,43 @@ static long dvb_net_ioctl(struct file *file,
 	return dvb_usercopy(file, cmd, arg, dvb_net_do_ioctl);
 }
 
+static int locked_dvb_net_open(struct inode *inode, struct file *file)
+{
+	struct dvb_device *dvbdev = file->private_data;
+	struct dvb_net *dvbnet = dvbdev->priv;
+	int ret;
+
+	if (mutex_lock_interruptible(&dvbnet->remove_mutex))
+		return -ERESTARTSYS;
+
+	if (dvbnet->exit) {
+		mutex_unlock(&dvbnet->remove_mutex);
+		return -ENODEV;
+	}
+
+	ret = dvb_generic_open(inode, file);
+
+	mutex_unlock(&dvbnet->remove_mutex);
+
+	return ret;
+}
+
 static int dvb_net_close(struct inode *inode, struct file *file)
 {
 	struct dvb_device *dvbdev = file->private_data;
 	struct dvb_net *dvbnet = dvbdev->priv;
 
+	mutex_lock(&dvbnet->remove_mutex);
+
 	dvb_generic_release(inode, file);
 
-	if(dvbdev->users == 1 && dvbnet->exit == 1)
+	if (dvbdev->users == 1 && dvbnet->exit == 1) {
+		mutex_unlock(&dvbnet->remove_mutex);
 		wake_up(&dvbdev->wait_queue);
+	} else {
+		mutex_unlock(&dvbnet->remove_mutex);
+	}
+
 	return 0;
 }
 
@@ -1591,7 +1619,7 @@ static int dvb_net_close(struct inode *inode, struct file *file)
 static const struct file_operations dvb_net_fops = {
 	.owner = THIS_MODULE,
 	.unlocked_ioctl = dvb_net_ioctl,
-	.open =	dvb_generic_open,
+	.open =	locked_dvb_net_open,
 	.release = dvb_net_close,
 	.llseek = noop_llseek,
 };
@@ -1610,10 +1638,13 @@ void dvb_net_release (struct dvb_net *dvbnet)
 {
 	int i;
 
+	mutex_lock(&dvbnet->remove_mutex);
 	dvbnet->exit = 1;
+	mutex_unlock(&dvbnet->remove_mutex);
+
 	if (dvbnet->dvbdev->users < 1)
 		wait_event(dvbnet->dvbdev->wait_queue,
-				dvbnet->dvbdev->users==1);
+				dvbnet->dvbdev->users == 1);
 
 	dvb_unregister_device(dvbnet->dvbdev);
 
@@ -1632,6 +1663,7 @@ int dvb_net_init (struct dvb_adapter *adap, struct dvb_net *dvbnet,
 	int i;
 
 	mutex_init(&dvbnet->ioctl_mutex);
+	mutex_init(&dvbnet->remove_mutex);
 	dvbnet->demux = dmx;
 
 	for (i=0; i<DVB_NET_DEVICES_MAX; i++)