All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH] media: em28xx: Fix race condition between open and init function
@ 2021-04-08 12:10 ` Igor Matheus Andrade Torrente
  0 siblings, 0 replies; 9+ messages in thread
From: Igor Matheus Andrade Torrente @ 2021-04-08 12:10 UTC (permalink / raw)
  To: mchehab
  Cc: Igor Matheus Andrade Torrente, linux-media, linux-kernel,
	linux-kernel-mentees, syzbot+b2391895514ed9ef4a8e

Fixes a race condition - for lack of a more precise term - between
em28xx_v4l2_open and em28xx_v4l2_init, by detaching the v4l2_dev,
media_pad and vdev structs from the em28xx_v4l2, and managing the
lifetime of those objects more dynamicaly.

The race happens when a thread[1] - containing the em28xx_v4l2_init()
code - calls the v4l2_mc_create_media_graph(), and it return a error,
if a thread[2] - running v4l2_open() - pass the verification point
and reaches the em28xx_v4l2_open() before the thread[1] finishes
the v4l2 subsystem deregistration, thread[1] will free all resources
before the em28xx_v4l2_open() can process their things,
because the em28xx_v4l2_init() has the dev->lock. And all this lead
the thread[2] to cause a user-after-free.

Reported-and-tested-by: syzbot+b2391895514ed9ef4a8e@syzkaller.appspotmail.com
Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
---
 drivers/media/usb/em28xx/em28xx-camera.c |   4 +-
 drivers/media/usb/em28xx/em28xx-video.c  | 188 ++++++++++++++---------
 drivers/media/usb/em28xx/em28xx.h        |   6 +-
 3 files changed, 123 insertions(+), 75 deletions(-)

diff --git a/drivers/media/usb/em28xx/em28xx-camera.c b/drivers/media/usb/em28xx/em28xx-camera.c
index d1e66b503f4d..436c5a8cbbb6 100644
--- a/drivers/media/usb/em28xx/em28xx-camera.c
+++ b/drivers/media/usb/em28xx/em28xx-camera.c
@@ -340,7 +340,7 @@ int em28xx_init_camera(struct em28xx *dev)
 		v4l2->sensor_xtal = 4300000;
 		pdata.xtal = v4l2->sensor_xtal;
 		if (NULL ==
-		    v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
+		    v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
 					      &mt9v011_info, NULL))
 			return -ENODEV;
 		v4l2->vinmode = EM28XX_VINMODE_RGB8_GRBG;
@@ -394,7 +394,7 @@ int em28xx_init_camera(struct em28xx *dev)
 		v4l2->sensor_yres = 480;
 
 		subdev =
-		     v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
+		     v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
 					       &ov2640_info, NULL);
 		if (!subdev)
 			return -ENODEV;
diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
index 6b84c3413e83..e1febb2bf06b 100644
--- a/drivers/media/usb/em28xx/em28xx-video.c
+++ b/drivers/media/usb/em28xx/em28xx-video.c
@@ -184,7 +184,7 @@ static int em28xx_vbi_supported(struct em28xx *dev)
  */
 static void em28xx_wake_i2c(struct em28xx *dev)
 {
-	struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
+	struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
 
 	v4l2_device_call_all(v4l2_dev, 0, core,  reset, 0);
 	v4l2_device_call_all(v4l2_dev, 0, video, s_routing,
@@ -974,9 +974,17 @@ static void em28xx_v4l2_create_entities(struct em28xx *dev)
 	struct em28xx_v4l2 *v4l2 = dev->v4l2;
 	int ret, i;
 
+	v4l2->video_pad = kzalloc(sizeof(*v4l2->video_pad), GFP_KERNEL);
+	if (!v4l2->video_pad) {
+		dev_err(&dev->intf->dev,
+			"failed to allocate video pad memory!\n");
+		v4l2->vdev->entity.num_pads = 0;
+		return;
+	}
+
 	/* Initialize Video, VBI and Radio pads */
-	v4l2->video_pad.flags = MEDIA_PAD_FL_SINK;
-	ret = media_entity_pads_init(&v4l2->vdev.entity, 1, &v4l2->video_pad);
+	v4l2->video_pad->flags = MEDIA_PAD_FL_SINK;
+	ret = media_entity_pads_init(&v4l2->vdev->entity, 1, v4l2->video_pad);
 	if (ret < 0)
 		dev_err(&dev->intf->dev,
 			"failed to initialize video media entity!\n");
@@ -1132,11 +1140,11 @@ int em28xx_start_analog_streaming(struct vb2_queue *vq, unsigned int count)
 			f.type = V4L2_TUNER_RADIO;
 		else
 			f.type = V4L2_TUNER_ANALOG_TV;
-		v4l2_device_call_all(&v4l2->v4l2_dev,
+		v4l2_device_call_all(v4l2->v4l2_dev,
 				     0, tuner, s_frequency, &f);
 
 		/* Enable video stream at TV decoder */
-		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 1);
+		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 1);
 	}
 
 	v4l2->streaming_users++;
@@ -1157,7 +1165,7 @@ static void em28xx_stop_streaming(struct vb2_queue *vq)
 
 	if (v4l2->streaming_users-- == 1) {
 		/* Disable video stream at TV decoder */
-		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
+		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
 
 		/* Last active user, so shutdown all the URBS */
 		em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
@@ -1192,7 +1200,7 @@ void em28xx_stop_vbi_streaming(struct vb2_queue *vq)
 
 	if (v4l2->streaming_users-- == 1) {
 		/* Disable video stream at TV decoder */
-		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
+		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
 
 		/* Last active user, so shutdown all the URBS */
 		em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
@@ -1286,7 +1294,7 @@ static int em28xx_vb2_setup(struct em28xx *dev)
 
 static void video_mux(struct em28xx *dev, int index)
 {
-	struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
+	struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
 
 	dev->ctl_input = index;
 	dev->ctl_ainput = INPUT(index)->amux;
@@ -1565,7 +1573,7 @@ static int vidioc_querystd(struct file *file, void *priv, v4l2_std_id *norm)
 {
 	struct em28xx *dev = video_drvdata(file);
 
-	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, video, querystd, norm);
+	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, video, querystd, norm);
 
 	return 0;
 }
@@ -1596,7 +1604,7 @@ static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id norm)
 		      &v4l2->hscale, &v4l2->vscale);
 
 	em28xx_resolution_set(dev);
-	v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
+	v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
 
 	return 0;
 }
@@ -1616,7 +1624,7 @@ static int vidioc_g_parm(struct file *file, void *priv,
 	p->parm.capture.readbuffers = EM28XX_MIN_BUF;
 	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
 	if (dev->is_webcam) {
-		rc = v4l2_device_call_until_err(&v4l2->v4l2_dev, 0,
+		rc = v4l2_device_call_until_err(v4l2->v4l2_dev, 0,
 						video, g_frame_interval, &ival);
 		if (!rc)
 			p->parm.capture.timeperframe = ival.interval;
@@ -1648,7 +1656,7 @@ static int vidioc_s_parm(struct file *file, void *priv,
 	memset(&p->parm, 0, sizeof(p->parm));
 	p->parm.capture.readbuffers = EM28XX_MIN_BUF;
 	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
-	rc = v4l2_device_call_until_err(&dev->v4l2->v4l2_dev, 0,
+	rc = v4l2_device_call_until_err(dev->v4l2->v4l2_dev, 0,
 					video, s_frame_interval, &ival);
 	if (!rc)
 		p->parm.capture.timeperframe = ival.interval;
@@ -1675,7 +1683,7 @@ static int vidioc_enum_input(struct file *file, void *priv,
 	if (INPUT(n)->type == EM28XX_VMUX_TELEVISION)
 		i->type = V4L2_INPUT_TYPE_TUNER;
 
-	i->std = dev->v4l2->vdev.tvnorms;
+	i->std = dev->v4l2->vdev->tvnorms;
 	/* webcams do not have the STD API */
 	if (dev->is_webcam)
 		i->capabilities = 0;
@@ -1839,7 +1847,7 @@ static int vidioc_g_tuner(struct file *file, void *priv,
 
 	strscpy(t->name, "Tuner", sizeof(t->name));
 
-	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
+	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
 	return 0;
 }
 
@@ -1851,7 +1859,7 @@ static int vidioc_s_tuner(struct file *file, void *priv,
 	if (t->index != 0)
 		return -EINVAL;
 
-	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
+	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
 	return 0;
 }
 
@@ -1878,8 +1886,8 @@ static int vidioc_s_frequency(struct file *file, void *priv,
 	if (f->tuner != 0)
 		return -EINVAL;
 
-	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_frequency, f);
-	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, g_frequency, &new_freq);
+	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_frequency, f);
+	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, g_frequency, &new_freq);
 	v4l2->frequency = new_freq.frequency;
 
 	return 0;
@@ -1897,7 +1905,7 @@ static int vidioc_g_chip_info(struct file *file, void *priv,
 		strscpy(chip->name, "ac97", sizeof(chip->name));
 	else
 		strscpy(chip->name,
-			dev->v4l2->v4l2_dev.name, sizeof(chip->name));
+			dev->v4l2->v4l2_dev->name, sizeof(chip->name));
 	return 0;
 }
 
@@ -2095,7 +2103,7 @@ static int radio_g_tuner(struct file *file, void *priv,
 
 	strscpy(t->name, "Radio", sizeof(t->name));
 
-	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
+	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
 
 	return 0;
 }
@@ -2108,7 +2116,7 @@ static int radio_s_tuner(struct file *file, void *priv,
 	if (t->index != 0)
 		return -EINVAL;
 
-	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
+	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
 
 	return 0;
 }
@@ -2160,6 +2168,11 @@ static int em28xx_v4l2_open(struct file *filp)
 	if (mutex_lock_interruptible(&dev->lock))
 		return -ERESTARTSYS;
 
+	if (!dev->v4l2) {
+		mutex_unlock(&dev->lock);
+		return -ENODEV;
+	}
+
 	ret = v4l2_fh_open(filp);
 	if (ret) {
 		dev_err(&dev->intf->dev,
@@ -2184,7 +2197,7 @@ static int em28xx_v4l2_open(struct file *filp)
 
 	if (vdev->vfl_type == VFL_TYPE_RADIO) {
 		em28xx_videodbg("video_open: setting radio device\n");
-		v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_radio);
+		v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_radio);
 	}
 
 	kref_get(&dev->ref);
@@ -2222,7 +2235,7 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
 
 	mutex_lock(&dev->lock);
 
-	v4l2_device_disconnect(&v4l2->v4l2_dev);
+	v4l2_device_disconnect(v4l2->v4l2_dev);
 
 	em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
 
@@ -2238,14 +2251,15 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
 			 video_device_node_name(&v4l2->vbi_dev));
 		video_unregister_device(&v4l2->vbi_dev);
 	}
-	if (video_is_registered(&v4l2->vdev)) {
+	if (video_is_registered(v4l2->vdev)) {
 		dev_info(&dev->intf->dev, "V4L2 device %s deregistered\n",
-			 video_device_node_name(&v4l2->vdev));
-		video_unregister_device(&v4l2->vdev);
+			 video_device_node_name(v4l2->vdev));
+		video_unregister_device(v4l2->vdev);
 	}
 
 	v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
-	v4l2_device_unregister(&v4l2->v4l2_dev);
+	v4l2_device_unregister(v4l2->v4l2_dev);
+	v4l2_device_put(v4l2->v4l2_dev);
 
 	kref_put(&v4l2->ref, em28xx_free_v4l2);
 
@@ -2305,7 +2319,7 @@ static int em28xx_v4l2_close(struct file *filp)
 			goto exit;
 
 		/* Save some power by putting tuner to sleep */
-		v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
+		v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
 
 		/* do this before setting alternate! */
 		em28xx_set_mode(dev, EM28XX_SUSPEND);
@@ -2330,6 +2344,17 @@ static int em28xx_v4l2_close(struct file *filp)
 	return 0;
 }
 
+void em28xx_vdev_release(struct video_device *vdev)
+{
+#ifdef CONFIG_MEDIA_CONTROLLER
+	int i;
+
+	for (i = 0; i < vdev->entity.num_pads; i++)
+		kfree(&vdev->entity.pads[i]);
+#endif
+	kfree(vdev);
+}
+
 static const struct v4l2_file_operations em28xx_v4l_fops = {
 	.owner         = THIS_MODULE,
 	.open          = em28xx_v4l2_open,
@@ -2387,7 +2412,7 @@ static const struct v4l2_ioctl_ops video_ioctl_ops = {
 static const struct video_device em28xx_video_template = {
 	.fops		= &em28xx_v4l_fops,
 	.ioctl_ops	= &video_ioctl_ops,
-	.release	= video_device_release_empty,
+	.release	= em28xx_vdev_release,
 	.tvnorms	= V4L2_STD_ALL,
 };
 
@@ -2445,7 +2470,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
 			     const char *type_name)
 {
 	*vfd		= *template;
-	vfd->v4l2_dev	= &dev->v4l2->v4l2_dev;
+	vfd->v4l2_dev	= dev->v4l2->v4l2_dev;
 	vfd->lock	= &dev->lock;
 	if (dev->is_webcam)
 		vfd->tvnorms = 0;
@@ -2459,7 +2484,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
 static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
 {
 	struct em28xx_v4l2      *v4l2 = dev->v4l2;
-	struct v4l2_device      *v4l2_dev = &v4l2->v4l2_dev;
+	struct v4l2_device      *v4l2_dev = v4l2->v4l2_dev;
 	struct tuner_setup      tun_setup;
 	struct v4l2_frequency   f;
 
@@ -2517,6 +2542,11 @@ static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
 	v4l2_device_call_all(v4l2_dev, 0, tuner, s_frequency, &f);
 }
 
+void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
+{
+	kfree(v4l2_dev);
+}
+
 static int em28xx_v4l2_init(struct em28xx *dev)
 {
 	u8 val;
@@ -2541,26 +2571,35 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 
 	v4l2 = kzalloc(sizeof(*v4l2), GFP_KERNEL);
 	if (!v4l2) {
-		mutex_unlock(&dev->lock);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto v4l2_error;
 	}
+
 	kref_init(&v4l2->ref);
 	v4l2->dev = dev;
 	dev->v4l2 = v4l2;
 
+	v4l2->v4l2_dev = kzalloc(sizeof(*v4l2->v4l2_dev), GFP_KERNEL);
+	if (!v4l2->v4l2_dev) {
+		ret = -ENOMEM;
+		goto v4l2_dev_error;
+	}
+
+	v4l2->v4l2_dev->release = em28xx_v4l2_dev_release;
+
 #ifdef CONFIG_MEDIA_CONTROLLER
-	v4l2->v4l2_dev.mdev = dev->media_dev;
+	v4l2->v4l2_dev->mdev = dev->media_dev;
 #endif
-	ret = v4l2_device_register(&dev->intf->dev, &v4l2->v4l2_dev);
+	ret = v4l2_device_register(&dev->intf->dev, v4l2->v4l2_dev);
 	if (ret < 0) {
 		dev_err(&dev->intf->dev,
 			"Call to v4l2_device_register() failed!\n");
-		goto err;
+		goto v4l2_device_register_error;
 	}
 
 	hdl = &v4l2->ctrl_handler;
 	v4l2_ctrl_handler_init(hdl, 8);
-	v4l2->v4l2_dev.ctrl_handler = hdl;
+	v4l2->v4l2_dev->ctrl_handler = hdl;
 
 	if (dev->is_webcam)
 		v4l2->progressive = true;
@@ -2575,22 +2614,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 	/* request some modules */
 
 	if (dev->has_msp34xx)
-		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 				    &dev->i2c_adap[dev->def_i2c_bus],
 				    "msp3400", 0, msp3400_addrs);
 
 	if (dev->board.decoder == EM28XX_SAA711X)
-		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 				    &dev->i2c_adap[dev->def_i2c_bus],
 				    "saa7115_auto", 0, saa711x_addrs);
 
 	if (dev->board.decoder == EM28XX_TVP5150)
-		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 				    &dev->i2c_adap[dev->def_i2c_bus],
 				    "tvp5150", 0, tvp5150_addrs);
 
 	if (dev->board.adecoder == EM28XX_TVAUDIO)
-		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 				    &dev->i2c_adap[dev->def_i2c_bus],
 				    "tvaudio", dev->board.tvaudio_addr, NULL);
 
@@ -2601,13 +2640,13 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 		int has_demod = (dev->board.tda9887_conf & TDA9887_PRESENT);
 
 		if (dev->board.radio.type)
-			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 					    &dev->i2c_adap[dev->def_i2c_bus],
 					    "tuner", dev->board.radio_addr,
 					    NULL);
 
 		if (has_demod)
-			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 					    &dev->i2c_adap[dev->def_i2c_bus],
 					    "tuner", 0,
 					    v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
@@ -2616,7 +2655,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 				has_demod ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
 			struct v4l2_subdev *sd;
 
-			sd = v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+			sd = v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 						 &dev->i2c_adap[dev->def_i2c_bus],
 						 "tuner", 0,
 						 v4l2_i2c_tuner_addrs(type));
@@ -2624,7 +2663,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 			if (sd)
 				tuner_addr = v4l2_i2c_subdev_addr(sd);
 		} else {
-			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 					    &dev->i2c_adap[dev->def_i2c_bus],
 					    "tuner", tuner_addr, NULL);
 		}
@@ -2686,7 +2725,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 
 	/* set default norm */
 	v4l2->norm = V4L2_STD_PAL;
-	v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
+	v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
 	v4l2->interlaced_fieldmode = EM28XX_INTERLACED_DEFAULT;
 
 	/* Analog specific initialization */
@@ -2756,40 +2795,45 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 		goto unregister_dev;
 
 	/* allocate and fill video video_device struct */
-	em28xx_vdev_init(dev, &v4l2->vdev, &em28xx_video_template, "video");
+	v4l2->vdev = kzalloc(sizeof(*v4l2->vdev), GFP_KERNEL);
+	if (!v4l2->vdev) {
+		ret = -ENOMEM;
+		goto unregister_dev;
+	}
+
+	em28xx_vdev_init(dev, v4l2->vdev, &em28xx_video_template, "video");
 	mutex_init(&v4l2->vb_queue_lock);
 	mutex_init(&v4l2->vb_vbi_queue_lock);
-	v4l2->vdev.queue = &v4l2->vb_vidq;
-	v4l2->vdev.queue->lock = &v4l2->vb_queue_lock;
-	v4l2->vdev.device_caps = V4L2_CAP_READWRITE | V4L2_CAP_VIDEO_CAPTURE |
+	v4l2->vdev->queue = &v4l2->vb_vidq;
+	v4l2->vdev->queue->lock = &v4l2->vb_queue_lock;
+	v4l2->vdev->device_caps = V4L2_CAP_READWRITE | V4L2_CAP_VIDEO_CAPTURE |
 				 V4L2_CAP_STREAMING;
 	if (dev->int_audio_type != EM28XX_INT_AUDIO_NONE)
-		v4l2->vdev.device_caps |= V4L2_CAP_AUDIO;
+		v4l2->vdev->device_caps |= V4L2_CAP_AUDIO;
 	if (dev->tuner_type != TUNER_ABSENT)
-		v4l2->vdev.device_caps |= V4L2_CAP_TUNER;
-
+		v4l2->vdev->device_caps |= V4L2_CAP_TUNER;
 
 	/* disable inapplicable ioctls */
 	if (dev->is_webcam) {
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_QUERYSTD);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_STD);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_STD);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_QUERYSTD);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_STD);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_STD);
 	} else {
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_PARM);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_PARM);
 	}
 	if (dev->tuner_type == TUNER_ABSENT) {
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_TUNER);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_TUNER);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_FREQUENCY);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_FREQUENCY);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_TUNER);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_TUNER);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_FREQUENCY);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_FREQUENCY);
 	}
 	if (dev->int_audio_type == EM28XX_INT_AUDIO_NONE) {
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_AUDIO);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_AUDIO);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_AUDIO);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_AUDIO);
 	}
 
 	/* register v4l2 video video_device */
-	ret = video_register_device(&v4l2->vdev, VFL_TYPE_VIDEO,
+	ret = video_register_device(v4l2->vdev, VFL_TYPE_VIDEO,
 				    video_nr[dev->devno]);
 	if (ret) {
 		dev_err(&dev->intf->dev,
@@ -2863,7 +2907,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 
 	dev_info(&dev->intf->dev,
 		 "V4L2 video device registered as %s\n",
-		 video_device_node_name(&v4l2->vdev));
+		 video_device_node_name(v4l2->vdev));
 
 	if (video_is_registered(&v4l2->vbi_dev))
 		dev_info(&dev->intf->dev,
@@ -2871,7 +2915,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 			 video_device_node_name(&v4l2->vbi_dev));
 
 	/* Save some power by putting tuner to sleep */
-	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
+	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
 
 	/* initialize videobuf2 stuff */
 	em28xx_vb2_setup(dev);
@@ -2897,18 +2941,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 			 video_device_node_name(&v4l2->vbi_dev));
 		video_unregister_device(&v4l2->vbi_dev);
 	}
-	if (video_is_registered(&v4l2->vdev)) {
+	if (video_is_registered(v4l2->vdev)) {
 		dev_info(&dev->intf->dev,
 			 "V4L2 device %s deregistered\n",
-			 video_device_node_name(&v4l2->vdev));
-		video_unregister_device(&v4l2->vdev);
+			 video_device_node_name(v4l2->vdev));
+		video_unregister_device(v4l2->vdev);
 	}
 
 	v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
-	v4l2_device_unregister(&v4l2->v4l2_dev);
-err:
+	v4l2_device_unregister(v4l2->v4l2_dev);
+
+v4l2_device_register_error:
+	v4l2_device_put(v4l2->v4l2_dev);
+v4l2_dev_error:
 	dev->v4l2 = NULL;
 	kref_put(&v4l2->ref, em28xx_free_v4l2);
+v4l2_error:
 	mutex_unlock(&dev->lock);
 	return ret;
 }
diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h
index 6648e11f1271..dbcc297b5a0d 100644
--- a/drivers/media/usb/em28xx/em28xx.h
+++ b/drivers/media/usb/em28xx/em28xx.h
@@ -552,10 +552,10 @@ struct em28xx_v4l2 {
 	struct kref ref;
 	struct em28xx *dev;
 
-	struct v4l2_device v4l2_dev;
+	struct v4l2_device *v4l2_dev;
 	struct v4l2_ctrl_handler ctrl_handler;
 
-	struct video_device vdev;
+	struct video_device *vdev;
 	struct video_device vbi_dev;
 	struct video_device radio_dev;
 
@@ -601,7 +601,7 @@ struct em28xx_v4l2 {
 	unsigned int field_count;
 
 #ifdef CONFIG_MEDIA_CONTROLLER
-	struct media_pad video_pad, vbi_pad;
+	struct media_pad *video_pad, vbi_pad;
 	struct media_entity *decoder;
 #endif
 };
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH] media: em28xx: Fix race condition between open and init function
@ 2021-04-08 12:10 ` Igor Matheus Andrade Torrente
  0 siblings, 0 replies; 9+ messages in thread
From: Igor Matheus Andrade Torrente @ 2021-04-08 12:10 UTC (permalink / raw)
  To: mchehab
  Cc: syzbot+b2391895514ed9ef4a8e, linux-media, linux-kernel-mentees,
	linux-kernel, Igor Matheus Andrade Torrente

Fixes a race condition - for lack of a more precise term - between
em28xx_v4l2_open and em28xx_v4l2_init, by detaching the v4l2_dev,
media_pad and vdev structs from the em28xx_v4l2, and managing the
lifetime of those objects more dynamicaly.

The race happens when a thread[1] - containing the em28xx_v4l2_init()
code - calls the v4l2_mc_create_media_graph(), and it return a error,
if a thread[2] - running v4l2_open() - pass the verification point
and reaches the em28xx_v4l2_open() before the thread[1] finishes
the v4l2 subsystem deregistration, thread[1] will free all resources
before the em28xx_v4l2_open() can process their things,
because the em28xx_v4l2_init() has the dev->lock. And all this lead
the thread[2] to cause a user-after-free.

Reported-and-tested-by: syzbot+b2391895514ed9ef4a8e@syzkaller.appspotmail.com
Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
---
 drivers/media/usb/em28xx/em28xx-camera.c |   4 +-
 drivers/media/usb/em28xx/em28xx-video.c  | 188 ++++++++++++++---------
 drivers/media/usb/em28xx/em28xx.h        |   6 +-
 3 files changed, 123 insertions(+), 75 deletions(-)

diff --git a/drivers/media/usb/em28xx/em28xx-camera.c b/drivers/media/usb/em28xx/em28xx-camera.c
index d1e66b503f4d..436c5a8cbbb6 100644
--- a/drivers/media/usb/em28xx/em28xx-camera.c
+++ b/drivers/media/usb/em28xx/em28xx-camera.c
@@ -340,7 +340,7 @@ int em28xx_init_camera(struct em28xx *dev)
 		v4l2->sensor_xtal = 4300000;
 		pdata.xtal = v4l2->sensor_xtal;
 		if (NULL ==
-		    v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
+		    v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
 					      &mt9v011_info, NULL))
 			return -ENODEV;
 		v4l2->vinmode = EM28XX_VINMODE_RGB8_GRBG;
@@ -394,7 +394,7 @@ int em28xx_init_camera(struct em28xx *dev)
 		v4l2->sensor_yres = 480;
 
 		subdev =
-		     v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
+		     v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
 					       &ov2640_info, NULL);
 		if (!subdev)
 			return -ENODEV;
diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
index 6b84c3413e83..e1febb2bf06b 100644
--- a/drivers/media/usb/em28xx/em28xx-video.c
+++ b/drivers/media/usb/em28xx/em28xx-video.c
@@ -184,7 +184,7 @@ static int em28xx_vbi_supported(struct em28xx *dev)
  */
 static void em28xx_wake_i2c(struct em28xx *dev)
 {
-	struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
+	struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
 
 	v4l2_device_call_all(v4l2_dev, 0, core,  reset, 0);
 	v4l2_device_call_all(v4l2_dev, 0, video, s_routing,
@@ -974,9 +974,17 @@ static void em28xx_v4l2_create_entities(struct em28xx *dev)
 	struct em28xx_v4l2 *v4l2 = dev->v4l2;
 	int ret, i;
 
+	v4l2->video_pad = kzalloc(sizeof(*v4l2->video_pad), GFP_KERNEL);
+	if (!v4l2->video_pad) {
+		dev_err(&dev->intf->dev,
+			"failed to allocate video pad memory!\n");
+		v4l2->vdev->entity.num_pads = 0;
+		return;
+	}
+
 	/* Initialize Video, VBI and Radio pads */
-	v4l2->video_pad.flags = MEDIA_PAD_FL_SINK;
-	ret = media_entity_pads_init(&v4l2->vdev.entity, 1, &v4l2->video_pad);
+	v4l2->video_pad->flags = MEDIA_PAD_FL_SINK;
+	ret = media_entity_pads_init(&v4l2->vdev->entity, 1, v4l2->video_pad);
 	if (ret < 0)
 		dev_err(&dev->intf->dev,
 			"failed to initialize video media entity!\n");
@@ -1132,11 +1140,11 @@ int em28xx_start_analog_streaming(struct vb2_queue *vq, unsigned int count)
 			f.type = V4L2_TUNER_RADIO;
 		else
 			f.type = V4L2_TUNER_ANALOG_TV;
-		v4l2_device_call_all(&v4l2->v4l2_dev,
+		v4l2_device_call_all(v4l2->v4l2_dev,
 				     0, tuner, s_frequency, &f);
 
 		/* Enable video stream at TV decoder */
-		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 1);
+		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 1);
 	}
 
 	v4l2->streaming_users++;
@@ -1157,7 +1165,7 @@ static void em28xx_stop_streaming(struct vb2_queue *vq)
 
 	if (v4l2->streaming_users-- == 1) {
 		/* Disable video stream at TV decoder */
-		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
+		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
 
 		/* Last active user, so shutdown all the URBS */
 		em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
@@ -1192,7 +1200,7 @@ void em28xx_stop_vbi_streaming(struct vb2_queue *vq)
 
 	if (v4l2->streaming_users-- == 1) {
 		/* Disable video stream at TV decoder */
-		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
+		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
 
 		/* Last active user, so shutdown all the URBS */
 		em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
@@ -1286,7 +1294,7 @@ static int em28xx_vb2_setup(struct em28xx *dev)
 
 static void video_mux(struct em28xx *dev, int index)
 {
-	struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
+	struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
 
 	dev->ctl_input = index;
 	dev->ctl_ainput = INPUT(index)->amux;
@@ -1565,7 +1573,7 @@ static int vidioc_querystd(struct file *file, void *priv, v4l2_std_id *norm)
 {
 	struct em28xx *dev = video_drvdata(file);
 
-	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, video, querystd, norm);
+	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, video, querystd, norm);
 
 	return 0;
 }
@@ -1596,7 +1604,7 @@ static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id norm)
 		      &v4l2->hscale, &v4l2->vscale);
 
 	em28xx_resolution_set(dev);
-	v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
+	v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
 
 	return 0;
 }
@@ -1616,7 +1624,7 @@ static int vidioc_g_parm(struct file *file, void *priv,
 	p->parm.capture.readbuffers = EM28XX_MIN_BUF;
 	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
 	if (dev->is_webcam) {
-		rc = v4l2_device_call_until_err(&v4l2->v4l2_dev, 0,
+		rc = v4l2_device_call_until_err(v4l2->v4l2_dev, 0,
 						video, g_frame_interval, &ival);
 		if (!rc)
 			p->parm.capture.timeperframe = ival.interval;
@@ -1648,7 +1656,7 @@ static int vidioc_s_parm(struct file *file, void *priv,
 	memset(&p->parm, 0, sizeof(p->parm));
 	p->parm.capture.readbuffers = EM28XX_MIN_BUF;
 	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
-	rc = v4l2_device_call_until_err(&dev->v4l2->v4l2_dev, 0,
+	rc = v4l2_device_call_until_err(dev->v4l2->v4l2_dev, 0,
 					video, s_frame_interval, &ival);
 	if (!rc)
 		p->parm.capture.timeperframe = ival.interval;
@@ -1675,7 +1683,7 @@ static int vidioc_enum_input(struct file *file, void *priv,
 	if (INPUT(n)->type == EM28XX_VMUX_TELEVISION)
 		i->type = V4L2_INPUT_TYPE_TUNER;
 
-	i->std = dev->v4l2->vdev.tvnorms;
+	i->std = dev->v4l2->vdev->tvnorms;
 	/* webcams do not have the STD API */
 	if (dev->is_webcam)
 		i->capabilities = 0;
@@ -1839,7 +1847,7 @@ static int vidioc_g_tuner(struct file *file, void *priv,
 
 	strscpy(t->name, "Tuner", sizeof(t->name));
 
-	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
+	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
 	return 0;
 }
 
@@ -1851,7 +1859,7 @@ static int vidioc_s_tuner(struct file *file, void *priv,
 	if (t->index != 0)
 		return -EINVAL;
 
-	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
+	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
 	return 0;
 }
 
@@ -1878,8 +1886,8 @@ static int vidioc_s_frequency(struct file *file, void *priv,
 	if (f->tuner != 0)
 		return -EINVAL;
 
-	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_frequency, f);
-	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, g_frequency, &new_freq);
+	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_frequency, f);
+	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, g_frequency, &new_freq);
 	v4l2->frequency = new_freq.frequency;
 
 	return 0;
@@ -1897,7 +1905,7 @@ static int vidioc_g_chip_info(struct file *file, void *priv,
 		strscpy(chip->name, "ac97", sizeof(chip->name));
 	else
 		strscpy(chip->name,
-			dev->v4l2->v4l2_dev.name, sizeof(chip->name));
+			dev->v4l2->v4l2_dev->name, sizeof(chip->name));
 	return 0;
 }
 
@@ -2095,7 +2103,7 @@ static int radio_g_tuner(struct file *file, void *priv,
 
 	strscpy(t->name, "Radio", sizeof(t->name));
 
-	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
+	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
 
 	return 0;
 }
@@ -2108,7 +2116,7 @@ static int radio_s_tuner(struct file *file, void *priv,
 	if (t->index != 0)
 		return -EINVAL;
 
-	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
+	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
 
 	return 0;
 }
@@ -2160,6 +2168,11 @@ static int em28xx_v4l2_open(struct file *filp)
 	if (mutex_lock_interruptible(&dev->lock))
 		return -ERESTARTSYS;
 
+	if (!dev->v4l2) {
+		mutex_unlock(&dev->lock);
+		return -ENODEV;
+	}
+
 	ret = v4l2_fh_open(filp);
 	if (ret) {
 		dev_err(&dev->intf->dev,
@@ -2184,7 +2197,7 @@ static int em28xx_v4l2_open(struct file *filp)
 
 	if (vdev->vfl_type == VFL_TYPE_RADIO) {
 		em28xx_videodbg("video_open: setting radio device\n");
-		v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_radio);
+		v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_radio);
 	}
 
 	kref_get(&dev->ref);
@@ -2222,7 +2235,7 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
 
 	mutex_lock(&dev->lock);
 
-	v4l2_device_disconnect(&v4l2->v4l2_dev);
+	v4l2_device_disconnect(v4l2->v4l2_dev);
 
 	em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
 
@@ -2238,14 +2251,15 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
 			 video_device_node_name(&v4l2->vbi_dev));
 		video_unregister_device(&v4l2->vbi_dev);
 	}
-	if (video_is_registered(&v4l2->vdev)) {
+	if (video_is_registered(v4l2->vdev)) {
 		dev_info(&dev->intf->dev, "V4L2 device %s deregistered\n",
-			 video_device_node_name(&v4l2->vdev));
-		video_unregister_device(&v4l2->vdev);
+			 video_device_node_name(v4l2->vdev));
+		video_unregister_device(v4l2->vdev);
 	}
 
 	v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
-	v4l2_device_unregister(&v4l2->v4l2_dev);
+	v4l2_device_unregister(v4l2->v4l2_dev);
+	v4l2_device_put(v4l2->v4l2_dev);
 
 	kref_put(&v4l2->ref, em28xx_free_v4l2);
 
@@ -2305,7 +2319,7 @@ static int em28xx_v4l2_close(struct file *filp)
 			goto exit;
 
 		/* Save some power by putting tuner to sleep */
-		v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
+		v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
 
 		/* do this before setting alternate! */
 		em28xx_set_mode(dev, EM28XX_SUSPEND);
@@ -2330,6 +2344,17 @@ static int em28xx_v4l2_close(struct file *filp)
 	return 0;
 }
 
+void em28xx_vdev_release(struct video_device *vdev)
+{
+#ifdef CONFIG_MEDIA_CONTROLLER
+	int i;
+
+	for (i = 0; i < vdev->entity.num_pads; i++)
+		kfree(&vdev->entity.pads[i]);
+#endif
+	kfree(vdev);
+}
+
 static const struct v4l2_file_operations em28xx_v4l_fops = {
 	.owner         = THIS_MODULE,
 	.open          = em28xx_v4l2_open,
@@ -2387,7 +2412,7 @@ static const struct v4l2_ioctl_ops video_ioctl_ops = {
 static const struct video_device em28xx_video_template = {
 	.fops		= &em28xx_v4l_fops,
 	.ioctl_ops	= &video_ioctl_ops,
-	.release	= video_device_release_empty,
+	.release	= em28xx_vdev_release,
 	.tvnorms	= V4L2_STD_ALL,
 };
 
@@ -2445,7 +2470,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
 			     const char *type_name)
 {
 	*vfd		= *template;
-	vfd->v4l2_dev	= &dev->v4l2->v4l2_dev;
+	vfd->v4l2_dev	= dev->v4l2->v4l2_dev;
 	vfd->lock	= &dev->lock;
 	if (dev->is_webcam)
 		vfd->tvnorms = 0;
@@ -2459,7 +2484,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
 static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
 {
 	struct em28xx_v4l2      *v4l2 = dev->v4l2;
-	struct v4l2_device      *v4l2_dev = &v4l2->v4l2_dev;
+	struct v4l2_device      *v4l2_dev = v4l2->v4l2_dev;
 	struct tuner_setup      tun_setup;
 	struct v4l2_frequency   f;
 
@@ -2517,6 +2542,11 @@ static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
 	v4l2_device_call_all(v4l2_dev, 0, tuner, s_frequency, &f);
 }
 
+void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
+{
+	kfree(v4l2_dev);
+}
+
 static int em28xx_v4l2_init(struct em28xx *dev)
 {
 	u8 val;
@@ -2541,26 +2571,35 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 
 	v4l2 = kzalloc(sizeof(*v4l2), GFP_KERNEL);
 	if (!v4l2) {
-		mutex_unlock(&dev->lock);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto v4l2_error;
 	}
+
 	kref_init(&v4l2->ref);
 	v4l2->dev = dev;
 	dev->v4l2 = v4l2;
 
+	v4l2->v4l2_dev = kzalloc(sizeof(*v4l2->v4l2_dev), GFP_KERNEL);
+	if (!v4l2->v4l2_dev) {
+		ret = -ENOMEM;
+		goto v4l2_dev_error;
+	}
+
+	v4l2->v4l2_dev->release = em28xx_v4l2_dev_release;
+
 #ifdef CONFIG_MEDIA_CONTROLLER
-	v4l2->v4l2_dev.mdev = dev->media_dev;
+	v4l2->v4l2_dev->mdev = dev->media_dev;
 #endif
-	ret = v4l2_device_register(&dev->intf->dev, &v4l2->v4l2_dev);
+	ret = v4l2_device_register(&dev->intf->dev, v4l2->v4l2_dev);
 	if (ret < 0) {
 		dev_err(&dev->intf->dev,
 			"Call to v4l2_device_register() failed!\n");
-		goto err;
+		goto v4l2_device_register_error;
 	}
 
 	hdl = &v4l2->ctrl_handler;
 	v4l2_ctrl_handler_init(hdl, 8);
-	v4l2->v4l2_dev.ctrl_handler = hdl;
+	v4l2->v4l2_dev->ctrl_handler = hdl;
 
 	if (dev->is_webcam)
 		v4l2->progressive = true;
@@ -2575,22 +2614,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 	/* request some modules */
 
 	if (dev->has_msp34xx)
-		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 				    &dev->i2c_adap[dev->def_i2c_bus],
 				    "msp3400", 0, msp3400_addrs);
 
 	if (dev->board.decoder == EM28XX_SAA711X)
-		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 				    &dev->i2c_adap[dev->def_i2c_bus],
 				    "saa7115_auto", 0, saa711x_addrs);
 
 	if (dev->board.decoder == EM28XX_TVP5150)
-		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 				    &dev->i2c_adap[dev->def_i2c_bus],
 				    "tvp5150", 0, tvp5150_addrs);
 
 	if (dev->board.adecoder == EM28XX_TVAUDIO)
-		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 				    &dev->i2c_adap[dev->def_i2c_bus],
 				    "tvaudio", dev->board.tvaudio_addr, NULL);
 
@@ -2601,13 +2640,13 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 		int has_demod = (dev->board.tda9887_conf & TDA9887_PRESENT);
 
 		if (dev->board.radio.type)
-			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 					    &dev->i2c_adap[dev->def_i2c_bus],
 					    "tuner", dev->board.radio_addr,
 					    NULL);
 
 		if (has_demod)
-			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 					    &dev->i2c_adap[dev->def_i2c_bus],
 					    "tuner", 0,
 					    v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
@@ -2616,7 +2655,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 				has_demod ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
 			struct v4l2_subdev *sd;
 
-			sd = v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+			sd = v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 						 &dev->i2c_adap[dev->def_i2c_bus],
 						 "tuner", 0,
 						 v4l2_i2c_tuner_addrs(type));
@@ -2624,7 +2663,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 			if (sd)
 				tuner_addr = v4l2_i2c_subdev_addr(sd);
 		} else {
-			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
+			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
 					    &dev->i2c_adap[dev->def_i2c_bus],
 					    "tuner", tuner_addr, NULL);
 		}
@@ -2686,7 +2725,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 
 	/* set default norm */
 	v4l2->norm = V4L2_STD_PAL;
-	v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
+	v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
 	v4l2->interlaced_fieldmode = EM28XX_INTERLACED_DEFAULT;
 
 	/* Analog specific initialization */
@@ -2756,40 +2795,45 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 		goto unregister_dev;
 
 	/* allocate and fill video video_device struct */
-	em28xx_vdev_init(dev, &v4l2->vdev, &em28xx_video_template, "video");
+	v4l2->vdev = kzalloc(sizeof(*v4l2->vdev), GFP_KERNEL);
+	if (!v4l2->vdev) {
+		ret = -ENOMEM;
+		goto unregister_dev;
+	}
+
+	em28xx_vdev_init(dev, v4l2->vdev, &em28xx_video_template, "video");
 	mutex_init(&v4l2->vb_queue_lock);
 	mutex_init(&v4l2->vb_vbi_queue_lock);
-	v4l2->vdev.queue = &v4l2->vb_vidq;
-	v4l2->vdev.queue->lock = &v4l2->vb_queue_lock;
-	v4l2->vdev.device_caps = V4L2_CAP_READWRITE | V4L2_CAP_VIDEO_CAPTURE |
+	v4l2->vdev->queue = &v4l2->vb_vidq;
+	v4l2->vdev->queue->lock = &v4l2->vb_queue_lock;
+	v4l2->vdev->device_caps = V4L2_CAP_READWRITE | V4L2_CAP_VIDEO_CAPTURE |
 				 V4L2_CAP_STREAMING;
 	if (dev->int_audio_type != EM28XX_INT_AUDIO_NONE)
-		v4l2->vdev.device_caps |= V4L2_CAP_AUDIO;
+		v4l2->vdev->device_caps |= V4L2_CAP_AUDIO;
 	if (dev->tuner_type != TUNER_ABSENT)
-		v4l2->vdev.device_caps |= V4L2_CAP_TUNER;
-
+		v4l2->vdev->device_caps |= V4L2_CAP_TUNER;
 
 	/* disable inapplicable ioctls */
 	if (dev->is_webcam) {
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_QUERYSTD);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_STD);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_STD);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_QUERYSTD);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_STD);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_STD);
 	} else {
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_PARM);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_PARM);
 	}
 	if (dev->tuner_type == TUNER_ABSENT) {
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_TUNER);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_TUNER);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_FREQUENCY);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_FREQUENCY);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_TUNER);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_TUNER);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_FREQUENCY);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_FREQUENCY);
 	}
 	if (dev->int_audio_type == EM28XX_INT_AUDIO_NONE) {
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_AUDIO);
-		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_AUDIO);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_AUDIO);
+		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_AUDIO);
 	}
 
 	/* register v4l2 video video_device */
-	ret = video_register_device(&v4l2->vdev, VFL_TYPE_VIDEO,
+	ret = video_register_device(v4l2->vdev, VFL_TYPE_VIDEO,
 				    video_nr[dev->devno]);
 	if (ret) {
 		dev_err(&dev->intf->dev,
@@ -2863,7 +2907,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 
 	dev_info(&dev->intf->dev,
 		 "V4L2 video device registered as %s\n",
-		 video_device_node_name(&v4l2->vdev));
+		 video_device_node_name(v4l2->vdev));
 
 	if (video_is_registered(&v4l2->vbi_dev))
 		dev_info(&dev->intf->dev,
@@ -2871,7 +2915,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 			 video_device_node_name(&v4l2->vbi_dev));
 
 	/* Save some power by putting tuner to sleep */
-	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
+	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
 
 	/* initialize videobuf2 stuff */
 	em28xx_vb2_setup(dev);
@@ -2897,18 +2941,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
 			 video_device_node_name(&v4l2->vbi_dev));
 		video_unregister_device(&v4l2->vbi_dev);
 	}
-	if (video_is_registered(&v4l2->vdev)) {
+	if (video_is_registered(v4l2->vdev)) {
 		dev_info(&dev->intf->dev,
 			 "V4L2 device %s deregistered\n",
-			 video_device_node_name(&v4l2->vdev));
-		video_unregister_device(&v4l2->vdev);
+			 video_device_node_name(v4l2->vdev));
+		video_unregister_device(v4l2->vdev);
 	}
 
 	v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
-	v4l2_device_unregister(&v4l2->v4l2_dev);
-err:
+	v4l2_device_unregister(v4l2->v4l2_dev);
+
+v4l2_device_register_error:
+	v4l2_device_put(v4l2->v4l2_dev);
+v4l2_dev_error:
 	dev->v4l2 = NULL;
 	kref_put(&v4l2->ref, em28xx_free_v4l2);
+v4l2_error:
 	mutex_unlock(&dev->lock);
 	return ret;
 }
diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h
index 6648e11f1271..dbcc297b5a0d 100644
--- a/drivers/media/usb/em28xx/em28xx.h
+++ b/drivers/media/usb/em28xx/em28xx.h
@@ -552,10 +552,10 @@ struct em28xx_v4l2 {
 	struct kref ref;
 	struct em28xx *dev;
 
-	struct v4l2_device v4l2_dev;
+	struct v4l2_device *v4l2_dev;
 	struct v4l2_ctrl_handler ctrl_handler;
 
-	struct video_device vdev;
+	struct video_device *vdev;
 	struct video_device vbi_dev;
 	struct video_device radio_dev;
 
@@ -601,7 +601,7 @@ struct em28xx_v4l2 {
 	unsigned int field_count;
 
 #ifdef CONFIG_MEDIA_CONTROLLER
-	struct media_pad video_pad, vbi_pad;
+	struct media_pad *video_pad, vbi_pad;
 	struct media_entity *decoder;
 #endif
 };
-- 
2.20.1

_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH] media: em28xx: Fix race condition between open and init function
  2021-04-08 12:10 ` Igor Matheus Andrade Torrente
  (?)
@ 2021-04-08 15:38   ` kernel test robot
  -1 siblings, 0 replies; 9+ messages in thread
From: kernel test robot @ 2021-04-08 15:38 UTC (permalink / raw)
  To: Igor Matheus Andrade Torrente, mchehab
  Cc: kbuild-all, clang-built-linux, Igor Matheus Andrade Torrente,
	linux-media, linux-kernel, linux-kernel-mentees,
	syzbot+b2391895514ed9ef4a8e

[-- Attachment #1: Type: text/plain, Size: 10319 bytes --]

Hi Igor,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linuxtv-media/master]
[also build test WARNING on v5.12-rc6 next-20210408]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Igor-Matheus-Andrade-Torrente/media-em28xx-Fix-race-condition-between-open-and-init-function/20210408-201217
base:   git://linuxtv.org/media_tree.git master
config: x86_64-randconfig-a014-20210408 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 56ea2e2fdd691136d5e6631fa0e447173694b82c)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/e13d07271a1ee4cbd8ac421bf575a36f9d0e1008
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Igor-Matheus-Andrade-Torrente/media-em28xx-Fix-race-condition-between-open-and-init-function/20210408-201217
        git checkout e13d07271a1ee4cbd8ac421bf575a36f9d0e1008
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/media/usb/em28xx/em28xx-video.c:2347:6: warning: no previous prototype for function 'em28xx_vdev_release' [-Wmissing-prototypes]
   void em28xx_vdev_release(struct video_device *vdev)
        ^
   drivers/media/usb/em28xx/em28xx-video.c:2347:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void em28xx_vdev_release(struct video_device *vdev)
   ^
   static 
>> drivers/media/usb/em28xx/em28xx-video.c:2545:6: warning: no previous prototype for function 'em28xx_v4l2_dev_release' [-Wmissing-prototypes]
   void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
        ^
   drivers/media/usb/em28xx/em28xx-video.c:2545:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
   ^
   static 
   2 warnings generated.


vim +/em28xx_vdev_release +2347 drivers/media/usb/em28xx/em28xx-video.c

  2346	
> 2347	void em28xx_vdev_release(struct video_device *vdev)
  2348	{
  2349	#ifdef CONFIG_MEDIA_CONTROLLER
  2350		int i;
  2351	
  2352		for (i = 0; i < vdev->entity.num_pads; i++)
  2353			kfree(&vdev->entity.pads[i]);
  2354	#endif
  2355		kfree(vdev);
  2356	}
  2357	
  2358	static const struct v4l2_file_operations em28xx_v4l_fops = {
  2359		.owner         = THIS_MODULE,
  2360		.open          = em28xx_v4l2_open,
  2361		.release       = em28xx_v4l2_close,
  2362		.read          = vb2_fop_read,
  2363		.poll          = vb2_fop_poll,
  2364		.mmap          = vb2_fop_mmap,
  2365		.unlocked_ioctl = video_ioctl2,
  2366	};
  2367	
  2368	static const struct v4l2_ioctl_ops video_ioctl_ops = {
  2369		.vidioc_querycap            = vidioc_querycap,
  2370		.vidioc_enum_fmt_vid_cap    = vidioc_enum_fmt_vid_cap,
  2371		.vidioc_g_fmt_vid_cap       = vidioc_g_fmt_vid_cap,
  2372		.vidioc_try_fmt_vid_cap     = vidioc_try_fmt_vid_cap,
  2373		.vidioc_s_fmt_vid_cap       = vidioc_s_fmt_vid_cap,
  2374		.vidioc_g_fmt_vbi_cap       = vidioc_g_fmt_vbi_cap,
  2375		.vidioc_try_fmt_vbi_cap     = vidioc_g_fmt_vbi_cap,
  2376		.vidioc_s_fmt_vbi_cap       = vidioc_g_fmt_vbi_cap,
  2377		.vidioc_enum_framesizes     = vidioc_enum_framesizes,
  2378		.vidioc_enumaudio           = vidioc_enumaudio,
  2379		.vidioc_g_audio             = vidioc_g_audio,
  2380		.vidioc_s_audio             = vidioc_s_audio,
  2381	
  2382		.vidioc_reqbufs             = vb2_ioctl_reqbufs,
  2383		.vidioc_create_bufs         = vb2_ioctl_create_bufs,
  2384		.vidioc_prepare_buf         = vb2_ioctl_prepare_buf,
  2385		.vidioc_querybuf            = vb2_ioctl_querybuf,
  2386		.vidioc_qbuf                = vb2_ioctl_qbuf,
  2387		.vidioc_dqbuf               = vb2_ioctl_dqbuf,
  2388	
  2389		.vidioc_g_std               = vidioc_g_std,
  2390		.vidioc_querystd            = vidioc_querystd,
  2391		.vidioc_s_std               = vidioc_s_std,
  2392		.vidioc_g_parm		    = vidioc_g_parm,
  2393		.vidioc_s_parm		    = vidioc_s_parm,
  2394		.vidioc_enum_input          = vidioc_enum_input,
  2395		.vidioc_g_input             = vidioc_g_input,
  2396		.vidioc_s_input             = vidioc_s_input,
  2397		.vidioc_streamon            = vb2_ioctl_streamon,
  2398		.vidioc_streamoff           = vb2_ioctl_streamoff,
  2399		.vidioc_g_tuner             = vidioc_g_tuner,
  2400		.vidioc_s_tuner             = vidioc_s_tuner,
  2401		.vidioc_g_frequency         = vidioc_g_frequency,
  2402		.vidioc_s_frequency         = vidioc_s_frequency,
  2403		.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
  2404		.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
  2405	#ifdef CONFIG_VIDEO_ADV_DEBUG
  2406		.vidioc_g_chip_info         = vidioc_g_chip_info,
  2407		.vidioc_g_register          = vidioc_g_register,
  2408		.vidioc_s_register          = vidioc_s_register,
  2409	#endif
  2410	};
  2411	
  2412	static const struct video_device em28xx_video_template = {
  2413		.fops		= &em28xx_v4l_fops,
  2414		.ioctl_ops	= &video_ioctl_ops,
  2415		.release	= em28xx_vdev_release,
  2416		.tvnorms	= V4L2_STD_ALL,
  2417	};
  2418	
  2419	static const struct v4l2_file_operations radio_fops = {
  2420		.owner         = THIS_MODULE,
  2421		.open          = em28xx_v4l2_open,
  2422		.release       = em28xx_v4l2_close,
  2423		.unlocked_ioctl = video_ioctl2,
  2424	};
  2425	
  2426	static const struct v4l2_ioctl_ops radio_ioctl_ops = {
  2427		.vidioc_querycap      = vidioc_querycap,
  2428		.vidioc_g_tuner       = radio_g_tuner,
  2429		.vidioc_s_tuner       = radio_s_tuner,
  2430		.vidioc_g_frequency   = vidioc_g_frequency,
  2431		.vidioc_s_frequency   = vidioc_s_frequency,
  2432		.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
  2433		.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
  2434	#ifdef CONFIG_VIDEO_ADV_DEBUG
  2435		.vidioc_g_chip_info   = vidioc_g_chip_info,
  2436		.vidioc_g_register    = vidioc_g_register,
  2437		.vidioc_s_register    = vidioc_s_register,
  2438	#endif
  2439	};
  2440	
  2441	static struct video_device em28xx_radio_template = {
  2442		.fops		= &radio_fops,
  2443		.ioctl_ops	= &radio_ioctl_ops,
  2444		.release	= video_device_release_empty,
  2445	};
  2446	
  2447	/* I2C possible address to saa7115, tvp5150, msp3400, tvaudio */
  2448	static unsigned short saa711x_addrs[] = {
  2449		0x4a >> 1, 0x48 >> 1,   /* SAA7111, SAA7111A and SAA7113 */
  2450		0x42 >> 1, 0x40 >> 1,   /* SAA7114, SAA7115 and SAA7118 */
  2451		I2C_CLIENT_END };
  2452	
  2453	static unsigned short tvp5150_addrs[] = {
  2454		0xb8 >> 1,
  2455		0xba >> 1,
  2456		I2C_CLIENT_END
  2457	};
  2458	
  2459	static unsigned short msp3400_addrs[] = {
  2460		0x80 >> 1,
  2461		0x88 >> 1,
  2462		I2C_CLIENT_END
  2463	};
  2464	
  2465	/******************************** usb interface ******************************/
  2466	
  2467	static void em28xx_vdev_init(struct em28xx *dev,
  2468				     struct video_device *vfd,
  2469				     const struct video_device *template,
  2470				     const char *type_name)
  2471	{
  2472		*vfd		= *template;
  2473		vfd->v4l2_dev	= dev->v4l2->v4l2_dev;
  2474		vfd->lock	= &dev->lock;
  2475		if (dev->is_webcam)
  2476			vfd->tvnorms = 0;
  2477	
  2478		snprintf(vfd->name, sizeof(vfd->name), "%s %s",
  2479			 dev_name(&dev->intf->dev), type_name);
  2480	
  2481		video_set_drvdata(vfd, dev);
  2482	}
  2483	
  2484	static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
  2485	{
  2486		struct em28xx_v4l2      *v4l2 = dev->v4l2;
  2487		struct v4l2_device      *v4l2_dev = v4l2->v4l2_dev;
  2488		struct tuner_setup      tun_setup;
  2489		struct v4l2_frequency   f;
  2490	
  2491		memset(&tun_setup, 0, sizeof(tun_setup));
  2492	
  2493		tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
  2494		tun_setup.tuner_callback = em28xx_tuner_callback;
  2495	
  2496		if (dev->board.radio.type) {
  2497			tun_setup.type = dev->board.radio.type;
  2498			tun_setup.addr = dev->board.radio_addr;
  2499	
  2500			v4l2_device_call_all(v4l2_dev,
  2501					     0, tuner, s_type_addr, &tun_setup);
  2502		}
  2503	
  2504		if (dev->tuner_type != TUNER_ABSENT && dev->tuner_type) {
  2505			tun_setup.type   = dev->tuner_type;
  2506			tun_setup.addr   = tuner_addr;
  2507	
  2508			v4l2_device_call_all(v4l2_dev,
  2509					     0, tuner, s_type_addr, &tun_setup);
  2510		}
  2511	
  2512		if (dev->board.tda9887_conf) {
  2513			struct v4l2_priv_tun_config tda9887_cfg;
  2514	
  2515			tda9887_cfg.tuner = TUNER_TDA9887;
  2516			tda9887_cfg.priv = &dev->board.tda9887_conf;
  2517	
  2518			v4l2_device_call_all(v4l2_dev,
  2519					     0, tuner, s_config, &tda9887_cfg);
  2520		}
  2521	
  2522		if (dev->tuner_type == TUNER_XC2028) {
  2523			struct v4l2_priv_tun_config  xc2028_cfg;
  2524			struct xc2028_ctrl           ctl;
  2525	
  2526			memset(&xc2028_cfg, 0, sizeof(xc2028_cfg));
  2527			memset(&ctl, 0, sizeof(ctl));
  2528	
  2529			em28xx_setup_xc3028(dev, &ctl);
  2530	
  2531			xc2028_cfg.tuner = TUNER_XC2028;
  2532			xc2028_cfg.priv  = &ctl;
  2533	
  2534			v4l2_device_call_all(v4l2_dev, 0, tuner, s_config, &xc2028_cfg);
  2535		}
  2536	
  2537		/* configure tuner */
  2538		f.tuner = 0;
  2539		f.type = V4L2_TUNER_ANALOG_TV;
  2540		f.frequency = 9076;     /* just a magic number */
  2541		v4l2->frequency = f.frequency;
  2542		v4l2_device_call_all(v4l2_dev, 0, tuner, s_frequency, &f);
  2543	}
  2544	
> 2545	void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
  2546	{
  2547		kfree(v4l2_dev);
  2548	}
  2549	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 46852 bytes --]

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] media: em28xx: Fix race condition between open and init function
@ 2021-04-08 15:38   ` kernel test robot
  0 siblings, 0 replies; 9+ messages in thread
From: kernel test robot @ 2021-04-08 15:38 UTC (permalink / raw)
  To: Igor Matheus Andrade Torrente, mchehab
  Cc: kbuild-all, linux-kernel, clang-built-linux,
	syzbot+b2391895514ed9ef4a8e, Igor Matheus Andrade Torrente,
	linux-kernel-mentees, linux-media

[-- Attachment #1: Type: text/plain, Size: 10319 bytes --]

Hi Igor,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linuxtv-media/master]
[also build test WARNING on v5.12-rc6 next-20210408]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Igor-Matheus-Andrade-Torrente/media-em28xx-Fix-race-condition-between-open-and-init-function/20210408-201217
base:   git://linuxtv.org/media_tree.git master
config: x86_64-randconfig-a014-20210408 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 56ea2e2fdd691136d5e6631fa0e447173694b82c)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/e13d07271a1ee4cbd8ac421bf575a36f9d0e1008
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Igor-Matheus-Andrade-Torrente/media-em28xx-Fix-race-condition-between-open-and-init-function/20210408-201217
        git checkout e13d07271a1ee4cbd8ac421bf575a36f9d0e1008
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/media/usb/em28xx/em28xx-video.c:2347:6: warning: no previous prototype for function 'em28xx_vdev_release' [-Wmissing-prototypes]
   void em28xx_vdev_release(struct video_device *vdev)
        ^
   drivers/media/usb/em28xx/em28xx-video.c:2347:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void em28xx_vdev_release(struct video_device *vdev)
   ^
   static 
>> drivers/media/usb/em28xx/em28xx-video.c:2545:6: warning: no previous prototype for function 'em28xx_v4l2_dev_release' [-Wmissing-prototypes]
   void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
        ^
   drivers/media/usb/em28xx/em28xx-video.c:2545:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
   ^
   static 
   2 warnings generated.


vim +/em28xx_vdev_release +2347 drivers/media/usb/em28xx/em28xx-video.c

  2346	
> 2347	void em28xx_vdev_release(struct video_device *vdev)
  2348	{
  2349	#ifdef CONFIG_MEDIA_CONTROLLER
  2350		int i;
  2351	
  2352		for (i = 0; i < vdev->entity.num_pads; i++)
  2353			kfree(&vdev->entity.pads[i]);
  2354	#endif
  2355		kfree(vdev);
  2356	}
  2357	
  2358	static const struct v4l2_file_operations em28xx_v4l_fops = {
  2359		.owner         = THIS_MODULE,
  2360		.open          = em28xx_v4l2_open,
  2361		.release       = em28xx_v4l2_close,
  2362		.read          = vb2_fop_read,
  2363		.poll          = vb2_fop_poll,
  2364		.mmap          = vb2_fop_mmap,
  2365		.unlocked_ioctl = video_ioctl2,
  2366	};
  2367	
  2368	static const struct v4l2_ioctl_ops video_ioctl_ops = {
  2369		.vidioc_querycap            = vidioc_querycap,
  2370		.vidioc_enum_fmt_vid_cap    = vidioc_enum_fmt_vid_cap,
  2371		.vidioc_g_fmt_vid_cap       = vidioc_g_fmt_vid_cap,
  2372		.vidioc_try_fmt_vid_cap     = vidioc_try_fmt_vid_cap,
  2373		.vidioc_s_fmt_vid_cap       = vidioc_s_fmt_vid_cap,
  2374		.vidioc_g_fmt_vbi_cap       = vidioc_g_fmt_vbi_cap,
  2375		.vidioc_try_fmt_vbi_cap     = vidioc_g_fmt_vbi_cap,
  2376		.vidioc_s_fmt_vbi_cap       = vidioc_g_fmt_vbi_cap,
  2377		.vidioc_enum_framesizes     = vidioc_enum_framesizes,
  2378		.vidioc_enumaudio           = vidioc_enumaudio,
  2379		.vidioc_g_audio             = vidioc_g_audio,
  2380		.vidioc_s_audio             = vidioc_s_audio,
  2381	
  2382		.vidioc_reqbufs             = vb2_ioctl_reqbufs,
  2383		.vidioc_create_bufs         = vb2_ioctl_create_bufs,
  2384		.vidioc_prepare_buf         = vb2_ioctl_prepare_buf,
  2385		.vidioc_querybuf            = vb2_ioctl_querybuf,
  2386		.vidioc_qbuf                = vb2_ioctl_qbuf,
  2387		.vidioc_dqbuf               = vb2_ioctl_dqbuf,
  2388	
  2389		.vidioc_g_std               = vidioc_g_std,
  2390		.vidioc_querystd            = vidioc_querystd,
  2391		.vidioc_s_std               = vidioc_s_std,
  2392		.vidioc_g_parm		    = vidioc_g_parm,
  2393		.vidioc_s_parm		    = vidioc_s_parm,
  2394		.vidioc_enum_input          = vidioc_enum_input,
  2395		.vidioc_g_input             = vidioc_g_input,
  2396		.vidioc_s_input             = vidioc_s_input,
  2397		.vidioc_streamon            = vb2_ioctl_streamon,
  2398		.vidioc_streamoff           = vb2_ioctl_streamoff,
  2399		.vidioc_g_tuner             = vidioc_g_tuner,
  2400		.vidioc_s_tuner             = vidioc_s_tuner,
  2401		.vidioc_g_frequency         = vidioc_g_frequency,
  2402		.vidioc_s_frequency         = vidioc_s_frequency,
  2403		.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
  2404		.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
  2405	#ifdef CONFIG_VIDEO_ADV_DEBUG
  2406		.vidioc_g_chip_info         = vidioc_g_chip_info,
  2407		.vidioc_g_register          = vidioc_g_register,
  2408		.vidioc_s_register          = vidioc_s_register,
  2409	#endif
  2410	};
  2411	
  2412	static const struct video_device em28xx_video_template = {
  2413		.fops		= &em28xx_v4l_fops,
  2414		.ioctl_ops	= &video_ioctl_ops,
  2415		.release	= em28xx_vdev_release,
  2416		.tvnorms	= V4L2_STD_ALL,
  2417	};
  2418	
  2419	static const struct v4l2_file_operations radio_fops = {
  2420		.owner         = THIS_MODULE,
  2421		.open          = em28xx_v4l2_open,
  2422		.release       = em28xx_v4l2_close,
  2423		.unlocked_ioctl = video_ioctl2,
  2424	};
  2425	
  2426	static const struct v4l2_ioctl_ops radio_ioctl_ops = {
  2427		.vidioc_querycap      = vidioc_querycap,
  2428		.vidioc_g_tuner       = radio_g_tuner,
  2429		.vidioc_s_tuner       = radio_s_tuner,
  2430		.vidioc_g_frequency   = vidioc_g_frequency,
  2431		.vidioc_s_frequency   = vidioc_s_frequency,
  2432		.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
  2433		.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
  2434	#ifdef CONFIG_VIDEO_ADV_DEBUG
  2435		.vidioc_g_chip_info   = vidioc_g_chip_info,
  2436		.vidioc_g_register    = vidioc_g_register,
  2437		.vidioc_s_register    = vidioc_s_register,
  2438	#endif
  2439	};
  2440	
  2441	static struct video_device em28xx_radio_template = {
  2442		.fops		= &radio_fops,
  2443		.ioctl_ops	= &radio_ioctl_ops,
  2444		.release	= video_device_release_empty,
  2445	};
  2446	
  2447	/* I2C possible address to saa7115, tvp5150, msp3400, tvaudio */
  2448	static unsigned short saa711x_addrs[] = {
  2449		0x4a >> 1, 0x48 >> 1,   /* SAA7111, SAA7111A and SAA7113 */
  2450		0x42 >> 1, 0x40 >> 1,   /* SAA7114, SAA7115 and SAA7118 */
  2451		I2C_CLIENT_END };
  2452	
  2453	static unsigned short tvp5150_addrs[] = {
  2454		0xb8 >> 1,
  2455		0xba >> 1,
  2456		I2C_CLIENT_END
  2457	};
  2458	
  2459	static unsigned short msp3400_addrs[] = {
  2460		0x80 >> 1,
  2461		0x88 >> 1,
  2462		I2C_CLIENT_END
  2463	};
  2464	
  2465	/******************************** usb interface ******************************/
  2466	
  2467	static void em28xx_vdev_init(struct em28xx *dev,
  2468				     struct video_device *vfd,
  2469				     const struct video_device *template,
  2470				     const char *type_name)
  2471	{
  2472		*vfd		= *template;
  2473		vfd->v4l2_dev	= dev->v4l2->v4l2_dev;
  2474		vfd->lock	= &dev->lock;
  2475		if (dev->is_webcam)
  2476			vfd->tvnorms = 0;
  2477	
  2478		snprintf(vfd->name, sizeof(vfd->name), "%s %s",
  2479			 dev_name(&dev->intf->dev), type_name);
  2480	
  2481		video_set_drvdata(vfd, dev);
  2482	}
  2483	
  2484	static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
  2485	{
  2486		struct em28xx_v4l2      *v4l2 = dev->v4l2;
  2487		struct v4l2_device      *v4l2_dev = v4l2->v4l2_dev;
  2488		struct tuner_setup      tun_setup;
  2489		struct v4l2_frequency   f;
  2490	
  2491		memset(&tun_setup, 0, sizeof(tun_setup));
  2492	
  2493		tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
  2494		tun_setup.tuner_callback = em28xx_tuner_callback;
  2495	
  2496		if (dev->board.radio.type) {
  2497			tun_setup.type = dev->board.radio.type;
  2498			tun_setup.addr = dev->board.radio_addr;
  2499	
  2500			v4l2_device_call_all(v4l2_dev,
  2501					     0, tuner, s_type_addr, &tun_setup);
  2502		}
  2503	
  2504		if (dev->tuner_type != TUNER_ABSENT && dev->tuner_type) {
  2505			tun_setup.type   = dev->tuner_type;
  2506			tun_setup.addr   = tuner_addr;
  2507	
  2508			v4l2_device_call_all(v4l2_dev,
  2509					     0, tuner, s_type_addr, &tun_setup);
  2510		}
  2511	
  2512		if (dev->board.tda9887_conf) {
  2513			struct v4l2_priv_tun_config tda9887_cfg;
  2514	
  2515			tda9887_cfg.tuner = TUNER_TDA9887;
  2516			tda9887_cfg.priv = &dev->board.tda9887_conf;
  2517	
  2518			v4l2_device_call_all(v4l2_dev,
  2519					     0, tuner, s_config, &tda9887_cfg);
  2520		}
  2521	
  2522		if (dev->tuner_type == TUNER_XC2028) {
  2523			struct v4l2_priv_tun_config  xc2028_cfg;
  2524			struct xc2028_ctrl           ctl;
  2525	
  2526			memset(&xc2028_cfg, 0, sizeof(xc2028_cfg));
  2527			memset(&ctl, 0, sizeof(ctl));
  2528	
  2529			em28xx_setup_xc3028(dev, &ctl);
  2530	
  2531			xc2028_cfg.tuner = TUNER_XC2028;
  2532			xc2028_cfg.priv  = &ctl;
  2533	
  2534			v4l2_device_call_all(v4l2_dev, 0, tuner, s_config, &xc2028_cfg);
  2535		}
  2536	
  2537		/* configure tuner */
  2538		f.tuner = 0;
  2539		f.type = V4L2_TUNER_ANALOG_TV;
  2540		f.frequency = 9076;     /* just a magic number */
  2541		v4l2->frequency = f.frequency;
  2542		v4l2_device_call_all(v4l2_dev, 0, tuner, s_frequency, &f);
  2543	}
  2544	
> 2545	void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
  2546	{
  2547		kfree(v4l2_dev);
  2548	}
  2549	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 46852 bytes --]

[-- Attachment #3: Type: text/plain, Size: 201 bytes --]

_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] media: em28xx: Fix race condition between open and init function
@ 2021-04-08 15:38   ` kernel test robot
  0 siblings, 0 replies; 9+ messages in thread
From: kernel test robot @ 2021-04-08 15:38 UTC (permalink / raw)
  To: kbuild-all

[-- Attachment #1: Type: text/plain, Size: 10579 bytes --]

Hi Igor,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linuxtv-media/master]
[also build test WARNING on v5.12-rc6 next-20210408]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Igor-Matheus-Andrade-Torrente/media-em28xx-Fix-race-condition-between-open-and-init-function/20210408-201217
base:   git://linuxtv.org/media_tree.git master
config: x86_64-randconfig-a014-20210408 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 56ea2e2fdd691136d5e6631fa0e447173694b82c)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/e13d07271a1ee4cbd8ac421bf575a36f9d0e1008
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Igor-Matheus-Andrade-Torrente/media-em28xx-Fix-race-condition-between-open-and-init-function/20210408-201217
        git checkout e13d07271a1ee4cbd8ac421bf575a36f9d0e1008
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

>> drivers/media/usb/em28xx/em28xx-video.c:2347:6: warning: no previous prototype for function 'em28xx_vdev_release' [-Wmissing-prototypes]
   void em28xx_vdev_release(struct video_device *vdev)
        ^
   drivers/media/usb/em28xx/em28xx-video.c:2347:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void em28xx_vdev_release(struct video_device *vdev)
   ^
   static 
>> drivers/media/usb/em28xx/em28xx-video.c:2545:6: warning: no previous prototype for function 'em28xx_v4l2_dev_release' [-Wmissing-prototypes]
   void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
        ^
   drivers/media/usb/em28xx/em28xx-video.c:2545:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
   ^
   static 
   2 warnings generated.


vim +/em28xx_vdev_release +2347 drivers/media/usb/em28xx/em28xx-video.c

  2346	
> 2347	void em28xx_vdev_release(struct video_device *vdev)
  2348	{
  2349	#ifdef CONFIG_MEDIA_CONTROLLER
  2350		int i;
  2351	
  2352		for (i = 0; i < vdev->entity.num_pads; i++)
  2353			kfree(&vdev->entity.pads[i]);
  2354	#endif
  2355		kfree(vdev);
  2356	}
  2357	
  2358	static const struct v4l2_file_operations em28xx_v4l_fops = {
  2359		.owner         = THIS_MODULE,
  2360		.open          = em28xx_v4l2_open,
  2361		.release       = em28xx_v4l2_close,
  2362		.read          = vb2_fop_read,
  2363		.poll          = vb2_fop_poll,
  2364		.mmap          = vb2_fop_mmap,
  2365		.unlocked_ioctl = video_ioctl2,
  2366	};
  2367	
  2368	static const struct v4l2_ioctl_ops video_ioctl_ops = {
  2369		.vidioc_querycap            = vidioc_querycap,
  2370		.vidioc_enum_fmt_vid_cap    = vidioc_enum_fmt_vid_cap,
  2371		.vidioc_g_fmt_vid_cap       = vidioc_g_fmt_vid_cap,
  2372		.vidioc_try_fmt_vid_cap     = vidioc_try_fmt_vid_cap,
  2373		.vidioc_s_fmt_vid_cap       = vidioc_s_fmt_vid_cap,
  2374		.vidioc_g_fmt_vbi_cap       = vidioc_g_fmt_vbi_cap,
  2375		.vidioc_try_fmt_vbi_cap     = vidioc_g_fmt_vbi_cap,
  2376		.vidioc_s_fmt_vbi_cap       = vidioc_g_fmt_vbi_cap,
  2377		.vidioc_enum_framesizes     = vidioc_enum_framesizes,
  2378		.vidioc_enumaudio           = vidioc_enumaudio,
  2379		.vidioc_g_audio             = vidioc_g_audio,
  2380		.vidioc_s_audio             = vidioc_s_audio,
  2381	
  2382		.vidioc_reqbufs             = vb2_ioctl_reqbufs,
  2383		.vidioc_create_bufs         = vb2_ioctl_create_bufs,
  2384		.vidioc_prepare_buf         = vb2_ioctl_prepare_buf,
  2385		.vidioc_querybuf            = vb2_ioctl_querybuf,
  2386		.vidioc_qbuf                = vb2_ioctl_qbuf,
  2387		.vidioc_dqbuf               = vb2_ioctl_dqbuf,
  2388	
  2389		.vidioc_g_std               = vidioc_g_std,
  2390		.vidioc_querystd            = vidioc_querystd,
  2391		.vidioc_s_std               = vidioc_s_std,
  2392		.vidioc_g_parm		    = vidioc_g_parm,
  2393		.vidioc_s_parm		    = vidioc_s_parm,
  2394		.vidioc_enum_input          = vidioc_enum_input,
  2395		.vidioc_g_input             = vidioc_g_input,
  2396		.vidioc_s_input             = vidioc_s_input,
  2397		.vidioc_streamon            = vb2_ioctl_streamon,
  2398		.vidioc_streamoff           = vb2_ioctl_streamoff,
  2399		.vidioc_g_tuner             = vidioc_g_tuner,
  2400		.vidioc_s_tuner             = vidioc_s_tuner,
  2401		.vidioc_g_frequency         = vidioc_g_frequency,
  2402		.vidioc_s_frequency         = vidioc_s_frequency,
  2403		.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
  2404		.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
  2405	#ifdef CONFIG_VIDEO_ADV_DEBUG
  2406		.vidioc_g_chip_info         = vidioc_g_chip_info,
  2407		.vidioc_g_register          = vidioc_g_register,
  2408		.vidioc_s_register          = vidioc_s_register,
  2409	#endif
  2410	};
  2411	
  2412	static const struct video_device em28xx_video_template = {
  2413		.fops		= &em28xx_v4l_fops,
  2414		.ioctl_ops	= &video_ioctl_ops,
  2415		.release	= em28xx_vdev_release,
  2416		.tvnorms	= V4L2_STD_ALL,
  2417	};
  2418	
  2419	static const struct v4l2_file_operations radio_fops = {
  2420		.owner         = THIS_MODULE,
  2421		.open          = em28xx_v4l2_open,
  2422		.release       = em28xx_v4l2_close,
  2423		.unlocked_ioctl = video_ioctl2,
  2424	};
  2425	
  2426	static const struct v4l2_ioctl_ops radio_ioctl_ops = {
  2427		.vidioc_querycap      = vidioc_querycap,
  2428		.vidioc_g_tuner       = radio_g_tuner,
  2429		.vidioc_s_tuner       = radio_s_tuner,
  2430		.vidioc_g_frequency   = vidioc_g_frequency,
  2431		.vidioc_s_frequency   = vidioc_s_frequency,
  2432		.vidioc_subscribe_event = v4l2_ctrl_subscribe_event,
  2433		.vidioc_unsubscribe_event = v4l2_event_unsubscribe,
  2434	#ifdef CONFIG_VIDEO_ADV_DEBUG
  2435		.vidioc_g_chip_info   = vidioc_g_chip_info,
  2436		.vidioc_g_register    = vidioc_g_register,
  2437		.vidioc_s_register    = vidioc_s_register,
  2438	#endif
  2439	};
  2440	
  2441	static struct video_device em28xx_radio_template = {
  2442		.fops		= &radio_fops,
  2443		.ioctl_ops	= &radio_ioctl_ops,
  2444		.release	= video_device_release_empty,
  2445	};
  2446	
  2447	/* I2C possible address to saa7115, tvp5150, msp3400, tvaudio */
  2448	static unsigned short saa711x_addrs[] = {
  2449		0x4a >> 1, 0x48 >> 1,   /* SAA7111, SAA7111A and SAA7113 */
  2450		0x42 >> 1, 0x40 >> 1,   /* SAA7114, SAA7115 and SAA7118 */
  2451		I2C_CLIENT_END };
  2452	
  2453	static unsigned short tvp5150_addrs[] = {
  2454		0xb8 >> 1,
  2455		0xba >> 1,
  2456		I2C_CLIENT_END
  2457	};
  2458	
  2459	static unsigned short msp3400_addrs[] = {
  2460		0x80 >> 1,
  2461		0x88 >> 1,
  2462		I2C_CLIENT_END
  2463	};
  2464	
  2465	/******************************** usb interface ******************************/
  2466	
  2467	static void em28xx_vdev_init(struct em28xx *dev,
  2468				     struct video_device *vfd,
  2469				     const struct video_device *template,
  2470				     const char *type_name)
  2471	{
  2472		*vfd		= *template;
  2473		vfd->v4l2_dev	= dev->v4l2->v4l2_dev;
  2474		vfd->lock	= &dev->lock;
  2475		if (dev->is_webcam)
  2476			vfd->tvnorms = 0;
  2477	
  2478		snprintf(vfd->name, sizeof(vfd->name), "%s %s",
  2479			 dev_name(&dev->intf->dev), type_name);
  2480	
  2481		video_set_drvdata(vfd, dev);
  2482	}
  2483	
  2484	static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
  2485	{
  2486		struct em28xx_v4l2      *v4l2 = dev->v4l2;
  2487		struct v4l2_device      *v4l2_dev = v4l2->v4l2_dev;
  2488		struct tuner_setup      tun_setup;
  2489		struct v4l2_frequency   f;
  2490	
  2491		memset(&tun_setup, 0, sizeof(tun_setup));
  2492	
  2493		tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
  2494		tun_setup.tuner_callback = em28xx_tuner_callback;
  2495	
  2496		if (dev->board.radio.type) {
  2497			tun_setup.type = dev->board.radio.type;
  2498			tun_setup.addr = dev->board.radio_addr;
  2499	
  2500			v4l2_device_call_all(v4l2_dev,
  2501					     0, tuner, s_type_addr, &tun_setup);
  2502		}
  2503	
  2504		if (dev->tuner_type != TUNER_ABSENT && dev->tuner_type) {
  2505			tun_setup.type   = dev->tuner_type;
  2506			tun_setup.addr   = tuner_addr;
  2507	
  2508			v4l2_device_call_all(v4l2_dev,
  2509					     0, tuner, s_type_addr, &tun_setup);
  2510		}
  2511	
  2512		if (dev->board.tda9887_conf) {
  2513			struct v4l2_priv_tun_config tda9887_cfg;
  2514	
  2515			tda9887_cfg.tuner = TUNER_TDA9887;
  2516			tda9887_cfg.priv = &dev->board.tda9887_conf;
  2517	
  2518			v4l2_device_call_all(v4l2_dev,
  2519					     0, tuner, s_config, &tda9887_cfg);
  2520		}
  2521	
  2522		if (dev->tuner_type == TUNER_XC2028) {
  2523			struct v4l2_priv_tun_config  xc2028_cfg;
  2524			struct xc2028_ctrl           ctl;
  2525	
  2526			memset(&xc2028_cfg, 0, sizeof(xc2028_cfg));
  2527			memset(&ctl, 0, sizeof(ctl));
  2528	
  2529			em28xx_setup_xc3028(dev, &ctl);
  2530	
  2531			xc2028_cfg.tuner = TUNER_XC2028;
  2532			xc2028_cfg.priv  = &ctl;
  2533	
  2534			v4l2_device_call_all(v4l2_dev, 0, tuner, s_config, &xc2028_cfg);
  2535		}
  2536	
  2537		/* configure tuner */
  2538		f.tuner = 0;
  2539		f.type = V4L2_TUNER_ANALOG_TV;
  2540		f.frequency = 9076;     /* just a magic number */
  2541		v4l2->frequency = f.frequency;
  2542		v4l2_device_call_all(v4l2_dev, 0, tuner, s_frequency, &f);
  2543	}
  2544	
> 2545	void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
  2546	{
  2547		kfree(v4l2_dev);
  2548	}
  2549	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

[-- Attachment #2: config.gz --]
[-- Type: application/gzip, Size: 46852 bytes --]

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] media: em28xx: Fix race condition between open and init function
  2021-04-08 12:10 ` Igor Matheus Andrade Torrente
@ 2021-04-08 17:37   ` Shuah Khan
  -1 siblings, 0 replies; 9+ messages in thread
From: Shuah Khan @ 2021-04-08 17:37 UTC (permalink / raw)
  To: Igor Matheus Andrade Torrente, mchehab
  Cc: syzbot+b2391895514ed9ef4a8e, linux-media, linux-kernel-mentees,
	linux-kernel, Shuah Khan

On 4/8/21 6:10 AM, Igor Matheus Andrade Torrente wrote:
> Fixes a race condition - for lack of a more precise term - between
> em28xx_v4l2_open and em28xx_v4l2_init, by detaching the v4l2_dev,
> media_pad and vdev structs from the em28xx_v4l2, and managing the
> lifetime of those objects more dynamicaly.
> 
> The race happens when a thread[1] - containing the em28xx_v4l2_init()
> code - calls the v4l2_mc_create_media_graph(), and it return a error,
> if a thread[2] - running v4l2_open() - pass the verification point
> and reaches the em28xx_v4l2_open() before the thread[1] finishes
> the v4l2 subsystem deregistration, thread[1] will free all resources
> before the em28xx_v4l2_open() can process their things,
> because the em28xx_v4l2_init() has the dev->lock. And all this lead
> the thread[2] to cause a user-after-free.
> 

Have you tried this patch with em28xx device? You will have to take into
account the dependencies between the subdevs using the v4l2_dev.

Also try rmmod invidual drivers - what happens if you were to rmmod a
subdev driver? With v4l2_dev is not embedded in v4l2, this could open
up memory leaks or user-after-frees.

> Reported-and-tested-by: syzbot+b2391895514ed9ef4a8e@syzkaller.appspotmail.com
> Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
> ---
>   drivers/media/usb/em28xx/em28xx-camera.c |   4 +-
>   drivers/media/usb/em28xx/em28xx-video.c  | 188 ++++++++++++++---------
>   drivers/media/usb/em28xx/em28xx.h        |   6 +-
>   3 files changed, 123 insertions(+), 75 deletions(-)
> 
> diff --git a/drivers/media/usb/em28xx/em28xx-camera.c b/drivers/media/usb/em28xx/em28xx-camera.c
> index d1e66b503f4d..436c5a8cbbb6 100644
> --- a/drivers/media/usb/em28xx/em28xx-camera.c
> +++ b/drivers/media/usb/em28xx/em28xx-camera.c
> @@ -340,7 +340,7 @@ int em28xx_init_camera(struct em28xx *dev)
>   		v4l2->sensor_xtal = 4300000;
>   		pdata.xtal = v4l2->sensor_xtal;
>   		if (NULL ==
> -		    v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
> +		    v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
>   					      &mt9v011_info, NULL))
>   			return -ENODEV;
>   		v4l2->vinmode = EM28XX_VINMODE_RGB8_GRBG;
> @@ -394,7 +394,7 @@ int em28xx_init_camera(struct em28xx *dev)
>   		v4l2->sensor_yres = 480;
>   
>   		subdev =
> -		     v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
> +		     v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
>   					       &ov2640_info, NULL);
>   		if (!subdev)
>   			return -ENODEV;
> diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
> index 6b84c3413e83..e1febb2bf06b 100644
> --- a/drivers/media/usb/em28xx/em28xx-video.c
> +++ b/drivers/media/usb/em28xx/em28xx-video.c
> @@ -184,7 +184,7 @@ static int em28xx_vbi_supported(struct em28xx *dev)
>    */
>   static void em28xx_wake_i2c(struct em28xx *dev)
>   {
> -	struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
> +	struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
>   
>   	v4l2_device_call_all(v4l2_dev, 0, core,  reset, 0);
>   	v4l2_device_call_all(v4l2_dev, 0, video, s_routing,
> @@ -974,9 +974,17 @@ static void em28xx_v4l2_create_entities(struct em28xx *dev)
>   	struct em28xx_v4l2 *v4l2 = dev->v4l2;
>   	int ret, i;
>   
> +	v4l2->video_pad = kzalloc(sizeof(*v4l2->video_pad), GFP_KERNEL);
> +	if (!v4l2->video_pad) {
> +		dev_err(&dev->intf->dev,
> +			"failed to allocate video pad memory!\n");
> +		v4l2->vdev->entity.num_pads = 0;
> +		return;
> +	}
> +
>   	/* Initialize Video, VBI and Radio pads */
> -	v4l2->video_pad.flags = MEDIA_PAD_FL_SINK;
> -	ret = media_entity_pads_init(&v4l2->vdev.entity, 1, &v4l2->video_pad);
> +	v4l2->video_pad->flags = MEDIA_PAD_FL_SINK;
> +	ret = media_entity_pads_init(&v4l2->vdev->entity, 1, v4l2->video_pad);
>   	if (ret < 0)
>   		dev_err(&dev->intf->dev,
>   			"failed to initialize video media entity!\n");
> @@ -1132,11 +1140,11 @@ int em28xx_start_analog_streaming(struct vb2_queue *vq, unsigned int count)
>   			f.type = V4L2_TUNER_RADIO;
>   		else
>   			f.type = V4L2_TUNER_ANALOG_TV;
> -		v4l2_device_call_all(&v4l2->v4l2_dev,
> +		v4l2_device_call_all(v4l2->v4l2_dev,
>   				     0, tuner, s_frequency, &f);
>   
>   		/* Enable video stream at TV decoder */
> -		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 1);
> +		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 1);
>   	}
>   
>   	v4l2->streaming_users++;
> @@ -1157,7 +1165,7 @@ static void em28xx_stop_streaming(struct vb2_queue *vq)
>   
>   	if (v4l2->streaming_users-- == 1) {
>   		/* Disable video stream at TV decoder */
> -		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
> +		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
>   
>   		/* Last active user, so shutdown all the URBS */
>   		em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
> @@ -1192,7 +1200,7 @@ void em28xx_stop_vbi_streaming(struct vb2_queue *vq)
>   
>   	if (v4l2->streaming_users-- == 1) {
>   		/* Disable video stream at TV decoder */
> -		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
> +		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
>   
>   		/* Last active user, so shutdown all the URBS */
>   		em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
> @@ -1286,7 +1294,7 @@ static int em28xx_vb2_setup(struct em28xx *dev)
>   
>   static void video_mux(struct em28xx *dev, int index)
>   {
> -	struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
> +	struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
>   
>   	dev->ctl_input = index;
>   	dev->ctl_ainput = INPUT(index)->amux;
> @@ -1565,7 +1573,7 @@ static int vidioc_querystd(struct file *file, void *priv, v4l2_std_id *norm)
>   {
>   	struct em28xx *dev = video_drvdata(file);
>   
> -	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, video, querystd, norm);
> +	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, video, querystd, norm);
>   
>   	return 0;
>   }
> @@ -1596,7 +1604,7 @@ static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id norm)
>   		      &v4l2->hscale, &v4l2->vscale);
>   
>   	em28xx_resolution_set(dev);
> -	v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
> +	v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>   
>   	return 0;
>   }
> @@ -1616,7 +1624,7 @@ static int vidioc_g_parm(struct file *file, void *priv,
>   	p->parm.capture.readbuffers = EM28XX_MIN_BUF;
>   	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
>   	if (dev->is_webcam) {
> -		rc = v4l2_device_call_until_err(&v4l2->v4l2_dev, 0,
> +		rc = v4l2_device_call_until_err(v4l2->v4l2_dev, 0,
>   						video, g_frame_interval, &ival);
>   		if (!rc)
>   			p->parm.capture.timeperframe = ival.interval;
> @@ -1648,7 +1656,7 @@ static int vidioc_s_parm(struct file *file, void *priv,
>   	memset(&p->parm, 0, sizeof(p->parm));
>   	p->parm.capture.readbuffers = EM28XX_MIN_BUF;
>   	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
> -	rc = v4l2_device_call_until_err(&dev->v4l2->v4l2_dev, 0,
> +	rc = v4l2_device_call_until_err(dev->v4l2->v4l2_dev, 0,
>   					video, s_frame_interval, &ival);
>   	if (!rc)
>   		p->parm.capture.timeperframe = ival.interval;
> @@ -1675,7 +1683,7 @@ static int vidioc_enum_input(struct file *file, void *priv,
>   	if (INPUT(n)->type == EM28XX_VMUX_TELEVISION)
>   		i->type = V4L2_INPUT_TYPE_TUNER;
>   
> -	i->std = dev->v4l2->vdev.tvnorms;
> +	i->std = dev->v4l2->vdev->tvnorms;
>   	/* webcams do not have the STD API */
>   	if (dev->is_webcam)
>   		i->capabilities = 0;
> @@ -1839,7 +1847,7 @@ static int vidioc_g_tuner(struct file *file, void *priv,
>   
>   	strscpy(t->name, "Tuner", sizeof(t->name));
>   
> -	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
> +	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>   	return 0;
>   }
>   
> @@ -1851,7 +1859,7 @@ static int vidioc_s_tuner(struct file *file, void *priv,
>   	if (t->index != 0)
>   		return -EINVAL;
>   
> -	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
> +	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>   	return 0;
>   }
>   
> @@ -1878,8 +1886,8 @@ static int vidioc_s_frequency(struct file *file, void *priv,
>   	if (f->tuner != 0)
>   		return -EINVAL;
>   
> -	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_frequency, f);
> -	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, g_frequency, &new_freq);
> +	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_frequency, f);
> +	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, g_frequency, &new_freq);
>   	v4l2->frequency = new_freq.frequency;
>   
>   	return 0;
> @@ -1897,7 +1905,7 @@ static int vidioc_g_chip_info(struct file *file, void *priv,
>   		strscpy(chip->name, "ac97", sizeof(chip->name));
>   	else
>   		strscpy(chip->name,
> -			dev->v4l2->v4l2_dev.name, sizeof(chip->name));
> +			dev->v4l2->v4l2_dev->name, sizeof(chip->name));
>   	return 0;
>   }
>   
> @@ -2095,7 +2103,7 @@ static int radio_g_tuner(struct file *file, void *priv,
>   
>   	strscpy(t->name, "Radio", sizeof(t->name));
>   
> -	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
> +	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>   
>   	return 0;
>   }
> @@ -2108,7 +2116,7 @@ static int radio_s_tuner(struct file *file, void *priv,
>   	if (t->index != 0)
>   		return -EINVAL;
>   
> -	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
> +	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>   
>   	return 0;
>   }
> @@ -2160,6 +2168,11 @@ static int em28xx_v4l2_open(struct file *filp)
>   	if (mutex_lock_interruptible(&dev->lock))
>   		return -ERESTARTSYS;
>   
> +	if (!dev->v4l2) {
> +		mutex_unlock(&dev->lock);
> +		return -ENODEV;
> +	}
> +
>   	ret = v4l2_fh_open(filp);
>   	if (ret) {
>   		dev_err(&dev->intf->dev,
> @@ -2184,7 +2197,7 @@ static int em28xx_v4l2_open(struct file *filp)
>   
>   	if (vdev->vfl_type == VFL_TYPE_RADIO) {
>   		em28xx_videodbg("video_open: setting radio device\n");
> -		v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_radio);
> +		v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_radio);
>   	}
>   
>   	kref_get(&dev->ref);
> @@ -2222,7 +2235,7 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
>   
>   	mutex_lock(&dev->lock);
>   
> -	v4l2_device_disconnect(&v4l2->v4l2_dev);
> +	v4l2_device_disconnect(v4l2->v4l2_dev);
>   
>   	em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
>   
> @@ -2238,14 +2251,15 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
>   			 video_device_node_name(&v4l2->vbi_dev));
>   		video_unregister_device(&v4l2->vbi_dev);
>   	}
> -	if (video_is_registered(&v4l2->vdev)) {
> +	if (video_is_registered(v4l2->vdev)) {
>   		dev_info(&dev->intf->dev, "V4L2 device %s deregistered\n",
> -			 video_device_node_name(&v4l2->vdev));
> -		video_unregister_device(&v4l2->vdev);
> +			 video_device_node_name(v4l2->vdev));
> +		video_unregister_device(v4l2->vdev);
>   	}
>   
>   	v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
> -	v4l2_device_unregister(&v4l2->v4l2_dev);
> +	v4l2_device_unregister(v4l2->v4l2_dev);
> +	v4l2_device_put(v4l2->v4l2_dev);
>   
>   	kref_put(&v4l2->ref, em28xx_free_v4l2);
>   
> @@ -2305,7 +2319,7 @@ static int em28xx_v4l2_close(struct file *filp)
>   			goto exit;
>   
>   		/* Save some power by putting tuner to sleep */
> -		v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
> +		v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
>   
>   		/* do this before setting alternate! */
>   		em28xx_set_mode(dev, EM28XX_SUSPEND);
> @@ -2330,6 +2344,17 @@ static int em28xx_v4l2_close(struct file *filp)
>   	return 0;
>   }
>   
> +void em28xx_vdev_release(struct video_device *vdev)
> +{
> +#ifdef CONFIG_MEDIA_CONTROLLER
> +	int i;
> +
> +	for (i = 0; i < vdev->entity.num_pads; i++)
> +		kfree(&vdev->entity.pads[i]);
> +#endif
> +	kfree(vdev);
> +}
> +
>   static const struct v4l2_file_operations em28xx_v4l_fops = {
>   	.owner         = THIS_MODULE,
>   	.open          = em28xx_v4l2_open,
> @@ -2387,7 +2412,7 @@ static const struct v4l2_ioctl_ops video_ioctl_ops = {
>   static const struct video_device em28xx_video_template = {
>   	.fops		= &em28xx_v4l_fops,
>   	.ioctl_ops	= &video_ioctl_ops,
> -	.release	= video_device_release_empty,
> +	.release	= em28xx_vdev_release,
>   	.tvnorms	= V4L2_STD_ALL,
>   };
>   
> @@ -2445,7 +2470,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
>   			     const char *type_name)
>   {
>   	*vfd		= *template;
> -	vfd->v4l2_dev	= &dev->v4l2->v4l2_dev;
> +	vfd->v4l2_dev	= dev->v4l2->v4l2_dev;
>   	vfd->lock	= &dev->lock;
>   	if (dev->is_webcam)
>   		vfd->tvnorms = 0;
> @@ -2459,7 +2484,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
>   static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
>   {
>   	struct em28xx_v4l2      *v4l2 = dev->v4l2;
> -	struct v4l2_device      *v4l2_dev = &v4l2->v4l2_dev;
> +	struct v4l2_device      *v4l2_dev = v4l2->v4l2_dev;
>   	struct tuner_setup      tun_setup;
>   	struct v4l2_frequency   f;
>   
> @@ -2517,6 +2542,11 @@ static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
>   	v4l2_device_call_all(v4l2_dev, 0, tuner, s_frequency, &f);
>   }
>   
> +void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
> +{
> +	kfree(v4l2_dev);
> +}
> +
>   static int em28xx_v4l2_init(struct em28xx *dev)
>   {
>   	u8 val;
> @@ -2541,26 +2571,35 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   
>   	v4l2 = kzalloc(sizeof(*v4l2), GFP_KERNEL);
>   	if (!v4l2) {
> -		mutex_unlock(&dev->lock);
> -		return -ENOMEM;
> +		ret = -ENOMEM;
> +		goto v4l2_error;
>   	}
> +
>   	kref_init(&v4l2->ref);
>   	v4l2->dev = dev;
>   	dev->v4l2 = v4l2;
>   
> +	v4l2->v4l2_dev = kzalloc(sizeof(*v4l2->v4l2_dev), GFP_KERNEL);
> +	if (!v4l2->v4l2_dev) {
> +		ret = -ENOMEM;
> +		goto v4l2_dev_error;
> +	}
> +
> +	v4l2->v4l2_dev->release = em28xx_v4l2_dev_release;
> +
>   #ifdef CONFIG_MEDIA_CONTROLLER
> -	v4l2->v4l2_dev.mdev = dev->media_dev;
> +	v4l2->v4l2_dev->mdev = dev->media_dev;
>   #endif
> -	ret = v4l2_device_register(&dev->intf->dev, &v4l2->v4l2_dev);
> +	ret = v4l2_device_register(&dev->intf->dev, v4l2->v4l2_dev);
>   	if (ret < 0) {
>   		dev_err(&dev->intf->dev,
>   			"Call to v4l2_device_register() failed!\n");
> -		goto err;
> +		goto v4l2_device_register_error;
>   	}
>   
>   	hdl = &v4l2->ctrl_handler;
>   	v4l2_ctrl_handler_init(hdl, 8);
> -	v4l2->v4l2_dev.ctrl_handler = hdl;
> +	v4l2->v4l2_dev->ctrl_handler = hdl;
>   
>   	if (dev->is_webcam)
>   		v4l2->progressive = true;
> @@ -2575,22 +2614,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   	/* request some modules */
>   
>   	if (dev->has_msp34xx)
> -		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   				    &dev->i2c_adap[dev->def_i2c_bus],
>   				    "msp3400", 0, msp3400_addrs);
>   
>   	if (dev->board.decoder == EM28XX_SAA711X)
> -		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   				    &dev->i2c_adap[dev->def_i2c_bus],
>   				    "saa7115_auto", 0, saa711x_addrs);
>   
>   	if (dev->board.decoder == EM28XX_TVP5150)
> -		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   				    &dev->i2c_adap[dev->def_i2c_bus],
>   				    "tvp5150", 0, tvp5150_addrs);
>   
>   	if (dev->board.adecoder == EM28XX_TVAUDIO)
> -		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   				    &dev->i2c_adap[dev->def_i2c_bus],
>   				    "tvaudio", dev->board.tvaudio_addr, NULL);
>   
> @@ -2601,13 +2640,13 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   		int has_demod = (dev->board.tda9887_conf & TDA9887_PRESENT);
>   
>   		if (dev->board.radio.type)
> -			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   					    &dev->i2c_adap[dev->def_i2c_bus],
>   					    "tuner", dev->board.radio_addr,
>   					    NULL);

Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
check error prior to this change to allocating v4l2_dev. Now this has
to be handled as a error leg.

>   
>   		if (has_demod)
> -			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   					    &dev->i2c_adap[dev->def_i2c_bus],
>   					    "tuner", 0,
>   					    v4l2_i2c_tuner_addrs(ADDRS_DEMOD));

Same here:

Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
check error prior to this change to allocating v4l2_dev. Now this has
to be handled as a error leg.

> @@ -2616,7 +2655,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   				has_demod ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
>   			struct v4l2_subdev *sd;
>   
> -			sd = v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +			sd = v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   						 &dev->i2c_adap[dev->def_i2c_bus],
>   						 "tuner", 0,
>   						 v4l2_i2c_tuner_addrs(type));
> @@ -2624,7 +2663,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   			if (sd)
>   				tuner_addr = v4l2_i2c_subdev_addr(sd);

Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
check error prior to this change to allocating v4l2_dev. Now this has
to be handled as a error leg.

>   		} else {
> -			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   					    &dev->i2c_adap[dev->def_i2c_bus],
>   					    "tuner", tuner_addr, NULL);

Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
check error prior to this change to allocating v4l2_dev. Now this has
to be handled as a error leg.

>   		}
> @@ -2686,7 +2725,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   
>   	/* set default norm */
>   	v4l2->norm = V4L2_STD_PAL;
> -	v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
> +	v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>   	v4l2->interlaced_fieldmode = EM28XX_INTERLACED_DEFAULT;
>   
>   	/* Analog specific initialization */
> @@ -2756,40 +2795,45 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   		goto unregister_dev;
>   
>   	/* allocate and fill video video_device struct */
> -	em28xx_vdev_init(dev, &v4l2->vdev, &em28xx_video_template, "video");
> +	v4l2->vdev = kzalloc(sizeof(*v4l2->vdev), GFP_KERNEL);
> +	if (!v4l2->vdev) {
> +		ret = -ENOMEM;
> +		goto unregister_dev;
> +	}
> +
> +	em28xx_vdev_init(dev, v4l2->vdev, &em28xx_video_template, "video");
>   	mutex_init(&v4l2->vb_queue_lock);
>   	mutex_init(&v4l2->vb_vbi_queue_lock);
> -	v4l2->vdev.queue = &v4l2->vb_vidq;
> -	v4l2->vdev.queue->lock = &v4l2->vb_queue_lock;
> -	v4l2->vdev.device_caps = V4L2_CAP_READWRITE | V4L2_CAP_VIDEO_CAPTURE |
> +	v4l2->vdev->queue = &v4l2->vb_vidq;
> +	v4l2->vdev->queue->lock = &v4l2->vb_queue_lock;
> +	v4l2->vdev->device_caps = V4L2_CAP_READWRITE | V4L2_CAP_VIDEO_CAPTURE |
>   				 V4L2_CAP_STREAMING;
>   	if (dev->int_audio_type != EM28XX_INT_AUDIO_NONE)
> -		v4l2->vdev.device_caps |= V4L2_CAP_AUDIO;
> +		v4l2->vdev->device_caps |= V4L2_CAP_AUDIO;
>   	if (dev->tuner_type != TUNER_ABSENT)
> -		v4l2->vdev.device_caps |= V4L2_CAP_TUNER;
> -
> +		v4l2->vdev->device_caps |= V4L2_CAP_TUNER;
>   
>   	/* disable inapplicable ioctls */
>   	if (dev->is_webcam) {
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_QUERYSTD);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_STD);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_STD);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_QUERYSTD);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_STD);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_STD);
>   	} else {
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_PARM);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_PARM);
>   	}
>   	if (dev->tuner_type == TUNER_ABSENT) {
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_TUNER);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_TUNER);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_FREQUENCY);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_FREQUENCY);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_TUNER);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_TUNER);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_FREQUENCY);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_FREQUENCY);
>   	}
>   	if (dev->int_audio_type == EM28XX_INT_AUDIO_NONE) {
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_AUDIO);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_AUDIO);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_AUDIO);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_AUDIO);
>   	}
>   
>   	/* register v4l2 video video_device */
> -	ret = video_register_device(&v4l2->vdev, VFL_TYPE_VIDEO,
> +	ret = video_register_device(v4l2->vdev, VFL_TYPE_VIDEO,
>   				    video_nr[dev->devno]);
>   	if (ret) {
>   		dev_err(&dev->intf->dev,
> @@ -2863,7 +2907,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   
>   	dev_info(&dev->intf->dev,
>   		 "V4L2 video device registered as %s\n",
> -		 video_device_node_name(&v4l2->vdev));
> +		 video_device_node_name(v4l2->vdev));
>   
>   	if (video_is_registered(&v4l2->vbi_dev))
>   		dev_info(&dev->intf->dev,
> @@ -2871,7 +2915,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   			 video_device_node_name(&v4l2->vbi_dev));
>   
>   	/* Save some power by putting tuner to sleep */
> -	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
> +	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
>   
>   	/* initialize videobuf2 stuff */
>   	em28xx_vb2_setup(dev);
> @@ -2897,18 +2941,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   			 video_device_node_name(&v4l2->vbi_dev));
>   		video_unregister_device(&v4l2->vbi_dev);
>   	}
> -	if (video_is_registered(&v4l2->vdev)) {
> +	if (video_is_registered(v4l2->vdev)) {
>   		dev_info(&dev->intf->dev,
>   			 "V4L2 device %s deregistered\n",
> -			 video_device_node_name(&v4l2->vdev));
> -		video_unregister_device(&v4l2->vdev);
> +			 video_device_node_name(v4l2->vdev));
> +		video_unregister_device(v4l2->vdev);
>   	}
>   
>   	v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
> -	v4l2_device_unregister(&v4l2->v4l2_dev);
> -err:
> +	v4l2_device_unregister(v4l2->v4l2_dev);
> +
> +v4l2_device_register_error:
> +	v4l2_device_put(v4l2->v4l2_dev);
> +v4l2_dev_error:
>   	dev->v4l2 = NULL;
>   	kref_put(&v4l2->ref, em28xx_free_v4l2);
> +v4l2_error:
>   	mutex_unlock(&dev->lock);
>   	return ret;
>   }
> diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h
> index 6648e11f1271..dbcc297b5a0d 100644
> --- a/drivers/media/usb/em28xx/em28xx.h
> +++ b/drivers/media/usb/em28xx/em28xx.h
> @@ -552,10 +552,10 @@ struct em28xx_v4l2 {
>   	struct kref ref;
>   	struct em28xx *dev;
>   
> -	struct v4l2_device v4l2_dev;
> +	struct v4l2_device *v4l2_dev;
>   	struct v4l2_ctrl_handler ctrl_handler;
>   
> -	struct video_device vdev;
> +	struct video_device *vdev;
>   	struct video_device vbi_dev;
>   	struct video_device radio_dev;
>   
> @@ -601,7 +601,7 @@ struct em28xx_v4l2 {
>   	unsigned int field_count;
>   
>   #ifdef CONFIG_MEDIA_CONTROLLER
> -	struct media_pad video_pad, vbi_pad;
> +	struct media_pad *video_pad, vbi_pad;
>   	struct media_entity *decoder;
>   #endif
>   };
> 

thanks,
-- Shuah

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] media: em28xx: Fix race condition between open and init function
@ 2021-04-08 17:37   ` Shuah Khan
  0 siblings, 0 replies; 9+ messages in thread
From: Shuah Khan @ 2021-04-08 17:37 UTC (permalink / raw)
  To: Igor Matheus Andrade Torrente, mchehab
  Cc: linux-media, linux-kernel-mentees, linux-kernel,
	syzbot+b2391895514ed9ef4a8e

On 4/8/21 6:10 AM, Igor Matheus Andrade Torrente wrote:
> Fixes a race condition - for lack of a more precise term - between
> em28xx_v4l2_open and em28xx_v4l2_init, by detaching the v4l2_dev,
> media_pad and vdev structs from the em28xx_v4l2, and managing the
> lifetime of those objects more dynamicaly.
> 
> The race happens when a thread[1] - containing the em28xx_v4l2_init()
> code - calls the v4l2_mc_create_media_graph(), and it return a error,
> if a thread[2] - running v4l2_open() - pass the verification point
> and reaches the em28xx_v4l2_open() before the thread[1] finishes
> the v4l2 subsystem deregistration, thread[1] will free all resources
> before the em28xx_v4l2_open() can process their things,
> because the em28xx_v4l2_init() has the dev->lock. And all this lead
> the thread[2] to cause a user-after-free.
> 

Have you tried this patch with em28xx device? You will have to take into
account the dependencies between the subdevs using the v4l2_dev.

Also try rmmod invidual drivers - what happens if you were to rmmod a
subdev driver? With v4l2_dev is not embedded in v4l2, this could open
up memory leaks or user-after-frees.

> Reported-and-tested-by: syzbot+b2391895514ed9ef4a8e@syzkaller.appspotmail.com
> Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
> ---
>   drivers/media/usb/em28xx/em28xx-camera.c |   4 +-
>   drivers/media/usb/em28xx/em28xx-video.c  | 188 ++++++++++++++---------
>   drivers/media/usb/em28xx/em28xx.h        |   6 +-
>   3 files changed, 123 insertions(+), 75 deletions(-)
> 
> diff --git a/drivers/media/usb/em28xx/em28xx-camera.c b/drivers/media/usb/em28xx/em28xx-camera.c
> index d1e66b503f4d..436c5a8cbbb6 100644
> --- a/drivers/media/usb/em28xx/em28xx-camera.c
> +++ b/drivers/media/usb/em28xx/em28xx-camera.c
> @@ -340,7 +340,7 @@ int em28xx_init_camera(struct em28xx *dev)
>   		v4l2->sensor_xtal = 4300000;
>   		pdata.xtal = v4l2->sensor_xtal;
>   		if (NULL ==
> -		    v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
> +		    v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
>   					      &mt9v011_info, NULL))
>   			return -ENODEV;
>   		v4l2->vinmode = EM28XX_VINMODE_RGB8_GRBG;
> @@ -394,7 +394,7 @@ int em28xx_init_camera(struct em28xx *dev)
>   		v4l2->sensor_yres = 480;
>   
>   		subdev =
> -		     v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
> +		     v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
>   					       &ov2640_info, NULL);
>   		if (!subdev)
>   			return -ENODEV;
> diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
> index 6b84c3413e83..e1febb2bf06b 100644
> --- a/drivers/media/usb/em28xx/em28xx-video.c
> +++ b/drivers/media/usb/em28xx/em28xx-video.c
> @@ -184,7 +184,7 @@ static int em28xx_vbi_supported(struct em28xx *dev)
>    */
>   static void em28xx_wake_i2c(struct em28xx *dev)
>   {
> -	struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
> +	struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
>   
>   	v4l2_device_call_all(v4l2_dev, 0, core,  reset, 0);
>   	v4l2_device_call_all(v4l2_dev, 0, video, s_routing,
> @@ -974,9 +974,17 @@ static void em28xx_v4l2_create_entities(struct em28xx *dev)
>   	struct em28xx_v4l2 *v4l2 = dev->v4l2;
>   	int ret, i;
>   
> +	v4l2->video_pad = kzalloc(sizeof(*v4l2->video_pad), GFP_KERNEL);
> +	if (!v4l2->video_pad) {
> +		dev_err(&dev->intf->dev,
> +			"failed to allocate video pad memory!\n");
> +		v4l2->vdev->entity.num_pads = 0;
> +		return;
> +	}
> +
>   	/* Initialize Video, VBI and Radio pads */
> -	v4l2->video_pad.flags = MEDIA_PAD_FL_SINK;
> -	ret = media_entity_pads_init(&v4l2->vdev.entity, 1, &v4l2->video_pad);
> +	v4l2->video_pad->flags = MEDIA_PAD_FL_SINK;
> +	ret = media_entity_pads_init(&v4l2->vdev->entity, 1, v4l2->video_pad);
>   	if (ret < 0)
>   		dev_err(&dev->intf->dev,
>   			"failed to initialize video media entity!\n");
> @@ -1132,11 +1140,11 @@ int em28xx_start_analog_streaming(struct vb2_queue *vq, unsigned int count)
>   			f.type = V4L2_TUNER_RADIO;
>   		else
>   			f.type = V4L2_TUNER_ANALOG_TV;
> -		v4l2_device_call_all(&v4l2->v4l2_dev,
> +		v4l2_device_call_all(v4l2->v4l2_dev,
>   				     0, tuner, s_frequency, &f);
>   
>   		/* Enable video stream at TV decoder */
> -		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 1);
> +		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 1);
>   	}
>   
>   	v4l2->streaming_users++;
> @@ -1157,7 +1165,7 @@ static void em28xx_stop_streaming(struct vb2_queue *vq)
>   
>   	if (v4l2->streaming_users-- == 1) {
>   		/* Disable video stream at TV decoder */
> -		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
> +		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
>   
>   		/* Last active user, so shutdown all the URBS */
>   		em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
> @@ -1192,7 +1200,7 @@ void em28xx_stop_vbi_streaming(struct vb2_queue *vq)
>   
>   	if (v4l2->streaming_users-- == 1) {
>   		/* Disable video stream at TV decoder */
> -		v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
> +		v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
>   
>   		/* Last active user, so shutdown all the URBS */
>   		em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
> @@ -1286,7 +1294,7 @@ static int em28xx_vb2_setup(struct em28xx *dev)
>   
>   static void video_mux(struct em28xx *dev, int index)
>   {
> -	struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
> +	struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
>   
>   	dev->ctl_input = index;
>   	dev->ctl_ainput = INPUT(index)->amux;
> @@ -1565,7 +1573,7 @@ static int vidioc_querystd(struct file *file, void *priv, v4l2_std_id *norm)
>   {
>   	struct em28xx *dev = video_drvdata(file);
>   
> -	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, video, querystd, norm);
> +	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, video, querystd, norm);
>   
>   	return 0;
>   }
> @@ -1596,7 +1604,7 @@ static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id norm)
>   		      &v4l2->hscale, &v4l2->vscale);
>   
>   	em28xx_resolution_set(dev);
> -	v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
> +	v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>   
>   	return 0;
>   }
> @@ -1616,7 +1624,7 @@ static int vidioc_g_parm(struct file *file, void *priv,
>   	p->parm.capture.readbuffers = EM28XX_MIN_BUF;
>   	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
>   	if (dev->is_webcam) {
> -		rc = v4l2_device_call_until_err(&v4l2->v4l2_dev, 0,
> +		rc = v4l2_device_call_until_err(v4l2->v4l2_dev, 0,
>   						video, g_frame_interval, &ival);
>   		if (!rc)
>   			p->parm.capture.timeperframe = ival.interval;
> @@ -1648,7 +1656,7 @@ static int vidioc_s_parm(struct file *file, void *priv,
>   	memset(&p->parm, 0, sizeof(p->parm));
>   	p->parm.capture.readbuffers = EM28XX_MIN_BUF;
>   	p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
> -	rc = v4l2_device_call_until_err(&dev->v4l2->v4l2_dev, 0,
> +	rc = v4l2_device_call_until_err(dev->v4l2->v4l2_dev, 0,
>   					video, s_frame_interval, &ival);
>   	if (!rc)
>   		p->parm.capture.timeperframe = ival.interval;
> @@ -1675,7 +1683,7 @@ static int vidioc_enum_input(struct file *file, void *priv,
>   	if (INPUT(n)->type == EM28XX_VMUX_TELEVISION)
>   		i->type = V4L2_INPUT_TYPE_TUNER;
>   
> -	i->std = dev->v4l2->vdev.tvnorms;
> +	i->std = dev->v4l2->vdev->tvnorms;
>   	/* webcams do not have the STD API */
>   	if (dev->is_webcam)
>   		i->capabilities = 0;
> @@ -1839,7 +1847,7 @@ static int vidioc_g_tuner(struct file *file, void *priv,
>   
>   	strscpy(t->name, "Tuner", sizeof(t->name));
>   
> -	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
> +	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>   	return 0;
>   }
>   
> @@ -1851,7 +1859,7 @@ static int vidioc_s_tuner(struct file *file, void *priv,
>   	if (t->index != 0)
>   		return -EINVAL;
>   
> -	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
> +	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>   	return 0;
>   }
>   
> @@ -1878,8 +1886,8 @@ static int vidioc_s_frequency(struct file *file, void *priv,
>   	if (f->tuner != 0)
>   		return -EINVAL;
>   
> -	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_frequency, f);
> -	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, g_frequency, &new_freq);
> +	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_frequency, f);
> +	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, g_frequency, &new_freq);
>   	v4l2->frequency = new_freq.frequency;
>   
>   	return 0;
> @@ -1897,7 +1905,7 @@ static int vidioc_g_chip_info(struct file *file, void *priv,
>   		strscpy(chip->name, "ac97", sizeof(chip->name));
>   	else
>   		strscpy(chip->name,
> -			dev->v4l2->v4l2_dev.name, sizeof(chip->name));
> +			dev->v4l2->v4l2_dev->name, sizeof(chip->name));
>   	return 0;
>   }
>   
> @@ -2095,7 +2103,7 @@ static int radio_g_tuner(struct file *file, void *priv,
>   
>   	strscpy(t->name, "Radio", sizeof(t->name));
>   
> -	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
> +	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>   
>   	return 0;
>   }
> @@ -2108,7 +2116,7 @@ static int radio_s_tuner(struct file *file, void *priv,
>   	if (t->index != 0)
>   		return -EINVAL;
>   
> -	v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
> +	v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>   
>   	return 0;
>   }
> @@ -2160,6 +2168,11 @@ static int em28xx_v4l2_open(struct file *filp)
>   	if (mutex_lock_interruptible(&dev->lock))
>   		return -ERESTARTSYS;
>   
> +	if (!dev->v4l2) {
> +		mutex_unlock(&dev->lock);
> +		return -ENODEV;
> +	}
> +
>   	ret = v4l2_fh_open(filp);
>   	if (ret) {
>   		dev_err(&dev->intf->dev,
> @@ -2184,7 +2197,7 @@ static int em28xx_v4l2_open(struct file *filp)
>   
>   	if (vdev->vfl_type == VFL_TYPE_RADIO) {
>   		em28xx_videodbg("video_open: setting radio device\n");
> -		v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_radio);
> +		v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_radio);
>   	}
>   
>   	kref_get(&dev->ref);
> @@ -2222,7 +2235,7 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
>   
>   	mutex_lock(&dev->lock);
>   
> -	v4l2_device_disconnect(&v4l2->v4l2_dev);
> +	v4l2_device_disconnect(v4l2->v4l2_dev);
>   
>   	em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
>   
> @@ -2238,14 +2251,15 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
>   			 video_device_node_name(&v4l2->vbi_dev));
>   		video_unregister_device(&v4l2->vbi_dev);
>   	}
> -	if (video_is_registered(&v4l2->vdev)) {
> +	if (video_is_registered(v4l2->vdev)) {
>   		dev_info(&dev->intf->dev, "V4L2 device %s deregistered\n",
> -			 video_device_node_name(&v4l2->vdev));
> -		video_unregister_device(&v4l2->vdev);
> +			 video_device_node_name(v4l2->vdev));
> +		video_unregister_device(v4l2->vdev);
>   	}
>   
>   	v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
> -	v4l2_device_unregister(&v4l2->v4l2_dev);
> +	v4l2_device_unregister(v4l2->v4l2_dev);
> +	v4l2_device_put(v4l2->v4l2_dev);
>   
>   	kref_put(&v4l2->ref, em28xx_free_v4l2);
>   
> @@ -2305,7 +2319,7 @@ static int em28xx_v4l2_close(struct file *filp)
>   			goto exit;
>   
>   		/* Save some power by putting tuner to sleep */
> -		v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
> +		v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
>   
>   		/* do this before setting alternate! */
>   		em28xx_set_mode(dev, EM28XX_SUSPEND);
> @@ -2330,6 +2344,17 @@ static int em28xx_v4l2_close(struct file *filp)
>   	return 0;
>   }
>   
> +void em28xx_vdev_release(struct video_device *vdev)
> +{
> +#ifdef CONFIG_MEDIA_CONTROLLER
> +	int i;
> +
> +	for (i = 0; i < vdev->entity.num_pads; i++)
> +		kfree(&vdev->entity.pads[i]);
> +#endif
> +	kfree(vdev);
> +}
> +
>   static const struct v4l2_file_operations em28xx_v4l_fops = {
>   	.owner         = THIS_MODULE,
>   	.open          = em28xx_v4l2_open,
> @@ -2387,7 +2412,7 @@ static const struct v4l2_ioctl_ops video_ioctl_ops = {
>   static const struct video_device em28xx_video_template = {
>   	.fops		= &em28xx_v4l_fops,
>   	.ioctl_ops	= &video_ioctl_ops,
> -	.release	= video_device_release_empty,
> +	.release	= em28xx_vdev_release,
>   	.tvnorms	= V4L2_STD_ALL,
>   };
>   
> @@ -2445,7 +2470,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
>   			     const char *type_name)
>   {
>   	*vfd		= *template;
> -	vfd->v4l2_dev	= &dev->v4l2->v4l2_dev;
> +	vfd->v4l2_dev	= dev->v4l2->v4l2_dev;
>   	vfd->lock	= &dev->lock;
>   	if (dev->is_webcam)
>   		vfd->tvnorms = 0;
> @@ -2459,7 +2484,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
>   static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
>   {
>   	struct em28xx_v4l2      *v4l2 = dev->v4l2;
> -	struct v4l2_device      *v4l2_dev = &v4l2->v4l2_dev;
> +	struct v4l2_device      *v4l2_dev = v4l2->v4l2_dev;
>   	struct tuner_setup      tun_setup;
>   	struct v4l2_frequency   f;
>   
> @@ -2517,6 +2542,11 @@ static void em28xx_tuner_setup(struct em28xx *dev, unsigned short tuner_addr)
>   	v4l2_device_call_all(v4l2_dev, 0, tuner, s_frequency, &f);
>   }
>   
> +void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
> +{
> +	kfree(v4l2_dev);
> +}
> +
>   static int em28xx_v4l2_init(struct em28xx *dev)
>   {
>   	u8 val;
> @@ -2541,26 +2571,35 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   
>   	v4l2 = kzalloc(sizeof(*v4l2), GFP_KERNEL);
>   	if (!v4l2) {
> -		mutex_unlock(&dev->lock);
> -		return -ENOMEM;
> +		ret = -ENOMEM;
> +		goto v4l2_error;
>   	}
> +
>   	kref_init(&v4l2->ref);
>   	v4l2->dev = dev;
>   	dev->v4l2 = v4l2;
>   
> +	v4l2->v4l2_dev = kzalloc(sizeof(*v4l2->v4l2_dev), GFP_KERNEL);
> +	if (!v4l2->v4l2_dev) {
> +		ret = -ENOMEM;
> +		goto v4l2_dev_error;
> +	}
> +
> +	v4l2->v4l2_dev->release = em28xx_v4l2_dev_release;
> +
>   #ifdef CONFIG_MEDIA_CONTROLLER
> -	v4l2->v4l2_dev.mdev = dev->media_dev;
> +	v4l2->v4l2_dev->mdev = dev->media_dev;
>   #endif
> -	ret = v4l2_device_register(&dev->intf->dev, &v4l2->v4l2_dev);
> +	ret = v4l2_device_register(&dev->intf->dev, v4l2->v4l2_dev);
>   	if (ret < 0) {
>   		dev_err(&dev->intf->dev,
>   			"Call to v4l2_device_register() failed!\n");
> -		goto err;
> +		goto v4l2_device_register_error;
>   	}
>   
>   	hdl = &v4l2->ctrl_handler;
>   	v4l2_ctrl_handler_init(hdl, 8);
> -	v4l2->v4l2_dev.ctrl_handler = hdl;
> +	v4l2->v4l2_dev->ctrl_handler = hdl;
>   
>   	if (dev->is_webcam)
>   		v4l2->progressive = true;
> @@ -2575,22 +2614,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   	/* request some modules */
>   
>   	if (dev->has_msp34xx)
> -		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   				    &dev->i2c_adap[dev->def_i2c_bus],
>   				    "msp3400", 0, msp3400_addrs);
>   
>   	if (dev->board.decoder == EM28XX_SAA711X)
> -		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   				    &dev->i2c_adap[dev->def_i2c_bus],
>   				    "saa7115_auto", 0, saa711x_addrs);
>   
>   	if (dev->board.decoder == EM28XX_TVP5150)
> -		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   				    &dev->i2c_adap[dev->def_i2c_bus],
>   				    "tvp5150", 0, tvp5150_addrs);
>   
>   	if (dev->board.adecoder == EM28XX_TVAUDIO)
> -		v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +		v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   				    &dev->i2c_adap[dev->def_i2c_bus],
>   				    "tvaudio", dev->board.tvaudio_addr, NULL);
>   
> @@ -2601,13 +2640,13 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   		int has_demod = (dev->board.tda9887_conf & TDA9887_PRESENT);
>   
>   		if (dev->board.radio.type)
> -			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   					    &dev->i2c_adap[dev->def_i2c_bus],
>   					    "tuner", dev->board.radio_addr,
>   					    NULL);

Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
check error prior to this change to allocating v4l2_dev. Now this has
to be handled as a error leg.

>   
>   		if (has_demod)
> -			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   					    &dev->i2c_adap[dev->def_i2c_bus],
>   					    "tuner", 0,
>   					    v4l2_i2c_tuner_addrs(ADDRS_DEMOD));

Same here:

Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
check error prior to this change to allocating v4l2_dev. Now this has
to be handled as a error leg.

> @@ -2616,7 +2655,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   				has_demod ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
>   			struct v4l2_subdev *sd;
>   
> -			sd = v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +			sd = v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   						 &dev->i2c_adap[dev->def_i2c_bus],
>   						 "tuner", 0,
>   						 v4l2_i2c_tuner_addrs(type));
> @@ -2624,7 +2663,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   			if (sd)
>   				tuner_addr = v4l2_i2c_subdev_addr(sd);

Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
check error prior to this change to allocating v4l2_dev. Now this has
to be handled as a error leg.

>   		} else {
> -			v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
> +			v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>   					    &dev->i2c_adap[dev->def_i2c_bus],
>   					    "tuner", tuner_addr, NULL);

Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
check error prior to this change to allocating v4l2_dev. Now this has
to be handled as a error leg.

>   		}
> @@ -2686,7 +2725,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   
>   	/* set default norm */
>   	v4l2->norm = V4L2_STD_PAL;
> -	v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
> +	v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>   	v4l2->interlaced_fieldmode = EM28XX_INTERLACED_DEFAULT;
>   
>   	/* Analog specific initialization */
> @@ -2756,40 +2795,45 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   		goto unregister_dev;
>   
>   	/* allocate and fill video video_device struct */
> -	em28xx_vdev_init(dev, &v4l2->vdev, &em28xx_video_template, "video");
> +	v4l2->vdev = kzalloc(sizeof(*v4l2->vdev), GFP_KERNEL);
> +	if (!v4l2->vdev) {
> +		ret = -ENOMEM;
> +		goto unregister_dev;
> +	}
> +
> +	em28xx_vdev_init(dev, v4l2->vdev, &em28xx_video_template, "video");
>   	mutex_init(&v4l2->vb_queue_lock);
>   	mutex_init(&v4l2->vb_vbi_queue_lock);
> -	v4l2->vdev.queue = &v4l2->vb_vidq;
> -	v4l2->vdev.queue->lock = &v4l2->vb_queue_lock;
> -	v4l2->vdev.device_caps = V4L2_CAP_READWRITE | V4L2_CAP_VIDEO_CAPTURE |
> +	v4l2->vdev->queue = &v4l2->vb_vidq;
> +	v4l2->vdev->queue->lock = &v4l2->vb_queue_lock;
> +	v4l2->vdev->device_caps = V4L2_CAP_READWRITE | V4L2_CAP_VIDEO_CAPTURE |
>   				 V4L2_CAP_STREAMING;
>   	if (dev->int_audio_type != EM28XX_INT_AUDIO_NONE)
> -		v4l2->vdev.device_caps |= V4L2_CAP_AUDIO;
> +		v4l2->vdev->device_caps |= V4L2_CAP_AUDIO;
>   	if (dev->tuner_type != TUNER_ABSENT)
> -		v4l2->vdev.device_caps |= V4L2_CAP_TUNER;
> -
> +		v4l2->vdev->device_caps |= V4L2_CAP_TUNER;
>   
>   	/* disable inapplicable ioctls */
>   	if (dev->is_webcam) {
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_QUERYSTD);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_STD);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_STD);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_QUERYSTD);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_STD);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_STD);
>   	} else {
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_PARM);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_PARM);
>   	}
>   	if (dev->tuner_type == TUNER_ABSENT) {
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_TUNER);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_TUNER);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_FREQUENCY);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_FREQUENCY);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_TUNER);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_TUNER);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_FREQUENCY);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_FREQUENCY);
>   	}
>   	if (dev->int_audio_type == EM28XX_INT_AUDIO_NONE) {
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_AUDIO);
> -		v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_AUDIO);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_AUDIO);
> +		v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_AUDIO);
>   	}
>   
>   	/* register v4l2 video video_device */
> -	ret = video_register_device(&v4l2->vdev, VFL_TYPE_VIDEO,
> +	ret = video_register_device(v4l2->vdev, VFL_TYPE_VIDEO,
>   				    video_nr[dev->devno]);
>   	if (ret) {
>   		dev_err(&dev->intf->dev,
> @@ -2863,7 +2907,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   
>   	dev_info(&dev->intf->dev,
>   		 "V4L2 video device registered as %s\n",
> -		 video_device_node_name(&v4l2->vdev));
> +		 video_device_node_name(v4l2->vdev));
>   
>   	if (video_is_registered(&v4l2->vbi_dev))
>   		dev_info(&dev->intf->dev,
> @@ -2871,7 +2915,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   			 video_device_node_name(&v4l2->vbi_dev));
>   
>   	/* Save some power by putting tuner to sleep */
> -	v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
> +	v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
>   
>   	/* initialize videobuf2 stuff */
>   	em28xx_vb2_setup(dev);
> @@ -2897,18 +2941,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>   			 video_device_node_name(&v4l2->vbi_dev));
>   		video_unregister_device(&v4l2->vbi_dev);
>   	}
> -	if (video_is_registered(&v4l2->vdev)) {
> +	if (video_is_registered(v4l2->vdev)) {
>   		dev_info(&dev->intf->dev,
>   			 "V4L2 device %s deregistered\n",
> -			 video_device_node_name(&v4l2->vdev));
> -		video_unregister_device(&v4l2->vdev);
> +			 video_device_node_name(v4l2->vdev));
> +		video_unregister_device(v4l2->vdev);
>   	}
>   
>   	v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
> -	v4l2_device_unregister(&v4l2->v4l2_dev);
> -err:
> +	v4l2_device_unregister(v4l2->v4l2_dev);
> +
> +v4l2_device_register_error:
> +	v4l2_device_put(v4l2->v4l2_dev);
> +v4l2_dev_error:
>   	dev->v4l2 = NULL;
>   	kref_put(&v4l2->ref, em28xx_free_v4l2);
> +v4l2_error:
>   	mutex_unlock(&dev->lock);
>   	return ret;
>   }
> diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h
> index 6648e11f1271..dbcc297b5a0d 100644
> --- a/drivers/media/usb/em28xx/em28xx.h
> +++ b/drivers/media/usb/em28xx/em28xx.h
> @@ -552,10 +552,10 @@ struct em28xx_v4l2 {
>   	struct kref ref;
>   	struct em28xx *dev;
>   
> -	struct v4l2_device v4l2_dev;
> +	struct v4l2_device *v4l2_dev;
>   	struct v4l2_ctrl_handler ctrl_handler;
>   
> -	struct video_device vdev;
> +	struct video_device *vdev;
>   	struct video_device vbi_dev;
>   	struct video_device radio_dev;
>   
> @@ -601,7 +601,7 @@ struct em28xx_v4l2 {
>   	unsigned int field_count;
>   
>   #ifdef CONFIG_MEDIA_CONTROLLER
> -	struct media_pad video_pad, vbi_pad;
> +	struct media_pad *video_pad, vbi_pad;
>   	struct media_entity *decoder;
>   #endif
>   };
> 

thanks,
-- Shuah
_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] media: em28xx: Fix race condition between open and init function
  2021-04-08 17:37   ` Shuah Khan
@ 2021-04-09 13:40     ` Igor Torrente
  -1 siblings, 0 replies; 9+ messages in thread
From: Igor Torrente @ 2021-04-09 13:40 UTC (permalink / raw)
  To: Shuah Khan, mchehab
  Cc: syzbot+b2391895514ed9ef4a8e, linux-media, linux-kernel-mentees,
	linux-kernel



On 4/8/21 2:37 PM, Shuah Khan wrote:
> On 4/8/21 6:10 AM, Igor Matheus Andrade Torrente wrote:
>> Fixes a race condition - for lack of a more precise term - between
>> em28xx_v4l2_open and em28xx_v4l2_init, by detaching the v4l2_dev,
>> media_pad and vdev structs from the em28xx_v4l2, and managing the
>> lifetime of those objects more dynamicaly.
>>
>> The race happens when a thread[1] - containing the em28xx_v4l2_init()
>> code - calls the v4l2_mc_create_media_graph(), and it return a error,
>> if a thread[2] - running v4l2_open() - pass the verification point
>> and reaches the em28xx_v4l2_open() before the thread[1] finishes
>> the v4l2 subsystem deregistration, thread[1] will free all resources
>> before the em28xx_v4l2_open() can process their things,
>> because the em28xx_v4l2_init() has the dev->lock. And all this lead
>> the thread[2] to cause a user-after-free.
>>
> 
> Have you tried this patch with em28xx device? You will have to take into
> account the dependencies between the subdevs using the v4l2_dev.
> 

No, I didn't because I don't have the device.
I was using the syzbot .c that produces this use-after-free.
I will try to modify the .c to test a complete initialization.

Actually, I forgot to put RFC alongside [PATCH].

> Also try rmmod invidual drivers - what happens if you were to rmmod a
> subdev driver? With v4l2_dev is not embedded in v4l2, this could open
> up memory leaks or user-after-frees.
> 

OK. Let me see what I can do.

>> Reported-and-tested-by: 
>> syzbot+b2391895514ed9ef4a8e@syzkaller.appspotmail.com
>> Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
>> ---
>>   drivers/media/usb/em28xx/em28xx-camera.c |   4 +-
>>   drivers/media/usb/em28xx/em28xx-video.c  | 188 ++++++++++++++---------
>>   drivers/media/usb/em28xx/em28xx.h        |   6 +-
>>   3 files changed, 123 insertions(+), 75 deletions(-)
>>
>> diff --git a/drivers/media/usb/em28xx/em28xx-camera.c 
>> b/drivers/media/usb/em28xx/em28xx-camera.c
>> index d1e66b503f4d..436c5a8cbbb6 100644
>> --- a/drivers/media/usb/em28xx/em28xx-camera.c
>> +++ b/drivers/media/usb/em28xx/em28xx-camera.c
>> @@ -340,7 +340,7 @@ int em28xx_init_camera(struct em28xx *dev)
>>           v4l2->sensor_xtal = 4300000;
>>           pdata.xtal = v4l2->sensor_xtal;
>>           if (NULL ==
>> -            v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
>> +            v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
>>                             &mt9v011_info, NULL))
>>               return -ENODEV;
>>           v4l2->vinmode = EM28XX_VINMODE_RGB8_GRBG;
>> @@ -394,7 +394,7 @@ int em28xx_init_camera(struct em28xx *dev)
>>           v4l2->sensor_yres = 480;
>>           subdev =
>> -             v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
>> +             v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
>>                              &ov2640_info, NULL);
>>           if (!subdev)
>>               return -ENODEV;
>> diff --git a/drivers/media/usb/em28xx/em28xx-video.c 
>> b/drivers/media/usb/em28xx/em28xx-video.c
>> index 6b84c3413e83..e1febb2bf06b 100644
>> --- a/drivers/media/usb/em28xx/em28xx-video.c
>> +++ b/drivers/media/usb/em28xx/em28xx-video.c
>> @@ -184,7 +184,7 @@ static int em28xx_vbi_supported(struct em28xx *dev)
>>    */
>>   static void em28xx_wake_i2c(struct em28xx *dev)
>>   {
>> -    struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
>> +    struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
>>       v4l2_device_call_all(v4l2_dev, 0, core,  reset, 0);
>>       v4l2_device_call_all(v4l2_dev, 0, video, s_routing,
>> @@ -974,9 +974,17 @@ static void em28xx_v4l2_create_entities(struct 
>> em28xx *dev)
>>       struct em28xx_v4l2 *v4l2 = dev->v4l2;
>>       int ret, i;
>> +    v4l2->video_pad = kzalloc(sizeof(*v4l2->video_pad), GFP_KERNEL);
>> +    if (!v4l2->video_pad) {
>> +        dev_err(&dev->intf->dev,
>> +            "failed to allocate video pad memory!\n");
>> +        v4l2->vdev->entity.num_pads = 0;
>> +        return;
>> +    }
>> +
>>       /* Initialize Video, VBI and Radio pads */
>> -    v4l2->video_pad.flags = MEDIA_PAD_FL_SINK;
>> -    ret = media_entity_pads_init(&v4l2->vdev.entity, 1, 
>> &v4l2->video_pad);
>> +    v4l2->video_pad->flags = MEDIA_PAD_FL_SINK;
>> +    ret = media_entity_pads_init(&v4l2->vdev->entity, 1, 
>> v4l2->video_pad);
>>       if (ret < 0)
>>           dev_err(&dev->intf->dev,
>>               "failed to initialize video media entity!\n");
>> @@ -1132,11 +1140,11 @@ int em28xx_start_analog_streaming(struct 
>> vb2_queue *vq, unsigned int count)
>>               f.type = V4L2_TUNER_RADIO;
>>           else
>>               f.type = V4L2_TUNER_ANALOG_TV;
>> -        v4l2_device_call_all(&v4l2->v4l2_dev,
>> +        v4l2_device_call_all(v4l2->v4l2_dev,
>>                        0, tuner, s_frequency, &f);
>>           /* Enable video stream at TV decoder */
>> -        v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 1);
>> +        v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 1);
>>       }
>>       v4l2->streaming_users++;
>> @@ -1157,7 +1165,7 @@ static void em28xx_stop_streaming(struct 
>> vb2_queue *vq)
>>       if (v4l2->streaming_users-- == 1) {
>>           /* Disable video stream at TV decoder */
>> -        v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
>> +        v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
>>           /* Last active user, so shutdown all the URBS */
>>           em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
>> @@ -1192,7 +1200,7 @@ void em28xx_stop_vbi_streaming(struct vb2_queue 
>> *vq)
>>       if (v4l2->streaming_users-- == 1) {
>>           /* Disable video stream at TV decoder */
>> -        v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
>> +        v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
>>           /* Last active user, so shutdown all the URBS */
>>           em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
>> @@ -1286,7 +1294,7 @@ static int em28xx_vb2_setup(struct em28xx *dev)
>>   static void video_mux(struct em28xx *dev, int index)
>>   {
>> -    struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
>> +    struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
>>       dev->ctl_input = index;
>>       dev->ctl_ainput = INPUT(index)->amux;
>> @@ -1565,7 +1573,7 @@ static int vidioc_querystd(struct file *file, 
>> void *priv, v4l2_std_id *norm)
>>   {
>>       struct em28xx *dev = video_drvdata(file);
>> -    v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, video, querystd, 
>> norm);
>> +    v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, video, querystd, norm);
>>       return 0;
>>   }
>> @@ -1596,7 +1604,7 @@ static int vidioc_s_std(struct file *file, void 
>> *priv, v4l2_std_id norm)
>>                 &v4l2->hscale, &v4l2->vscale);
>>       em28xx_resolution_set(dev);
>> -    v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>> +    v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>>       return 0;
>>   }
>> @@ -1616,7 +1624,7 @@ static int vidioc_g_parm(struct file *file, void 
>> *priv,
>>       p->parm.capture.readbuffers = EM28XX_MIN_BUF;
>>       p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
>>       if (dev->is_webcam) {
>> -        rc = v4l2_device_call_until_err(&v4l2->v4l2_dev, 0,
>> +        rc = v4l2_device_call_until_err(v4l2->v4l2_dev, 0,
>>                           video, g_frame_interval, &ival);
>>           if (!rc)
>>               p->parm.capture.timeperframe = ival.interval;
>> @@ -1648,7 +1656,7 @@ static int vidioc_s_parm(struct file *file, void 
>> *priv,
>>       memset(&p->parm, 0, sizeof(p->parm));
>>       p->parm.capture.readbuffers = EM28XX_MIN_BUF;
>>       p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
>> -    rc = v4l2_device_call_until_err(&dev->v4l2->v4l2_dev, 0,
>> +    rc = v4l2_device_call_until_err(dev->v4l2->v4l2_dev, 0,
>>                       video, s_frame_interval, &ival);
>>       if (!rc)
>>           p->parm.capture.timeperframe = ival.interval;
>> @@ -1675,7 +1683,7 @@ static int vidioc_enum_input(struct file *file, 
>> void *priv,
>>       if (INPUT(n)->type == EM28XX_VMUX_TELEVISION)
>>           i->type = V4L2_INPUT_TYPE_TUNER;
>> -    i->std = dev->v4l2->vdev.tvnorms;
>> +    i->std = dev->v4l2->vdev->tvnorms;
>>       /* webcams do not have the STD API */
>>       if (dev->is_webcam)
>>           i->capabilities = 0;
>> @@ -1839,7 +1847,7 @@ static int vidioc_g_tuner(struct file *file, 
>> void *priv,
>>       strscpy(t->name, "Tuner", sizeof(t->name));
>> -    v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>> +    v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>>       return 0;
>>   }
>> @@ -1851,7 +1859,7 @@ static int vidioc_s_tuner(struct file *file, 
>> void *priv,
>>       if (t->index != 0)
>>           return -EINVAL;
>> -    v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>> +    v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>>       return 0;
>>   }
>> @@ -1878,8 +1886,8 @@ static int vidioc_s_frequency(struct file *file, 
>> void *priv,
>>       if (f->tuner != 0)
>>           return -EINVAL;
>> -    v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_frequency, f);
>> -    v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, g_frequency, 
>> &new_freq);
>> +    v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_frequency, f);
>> +    v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, g_frequency, 
>> &new_freq);
>>       v4l2->frequency = new_freq.frequency;
>>       return 0;
>> @@ -1897,7 +1905,7 @@ static int vidioc_g_chip_info(struct file *file, 
>> void *priv,
>>           strscpy(chip->name, "ac97", sizeof(chip->name));
>>       else
>>           strscpy(chip->name,
>> -            dev->v4l2->v4l2_dev.name, sizeof(chip->name));
>> +            dev->v4l2->v4l2_dev->name, sizeof(chip->name));
>>       return 0;
>>   }
>> @@ -2095,7 +2103,7 @@ static int radio_g_tuner(struct file *file, void 
>> *priv,
>>       strscpy(t->name, "Radio", sizeof(t->name));
>> -    v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>> +    v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>>       return 0;
>>   }
>> @@ -2108,7 +2116,7 @@ static int radio_s_tuner(struct file *file, void 
>> *priv,
>>       if (t->index != 0)
>>           return -EINVAL;
>> -    v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>> +    v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>>       return 0;
>>   }
>> @@ -2160,6 +2168,11 @@ static int em28xx_v4l2_open(struct file *filp)
>>       if (mutex_lock_interruptible(&dev->lock))
>>           return -ERESTARTSYS;
>> +    if (!dev->v4l2) {
>> +        mutex_unlock(&dev->lock);
>> +        return -ENODEV;
>> +    }
>> +
>>       ret = v4l2_fh_open(filp);
>>       if (ret) {
>>           dev_err(&dev->intf->dev,
>> @@ -2184,7 +2197,7 @@ static int em28xx_v4l2_open(struct file *filp)
>>       if (vdev->vfl_type == VFL_TYPE_RADIO) {
>>           em28xx_videodbg("video_open: setting radio device\n");
>> -        v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_radio);
>> +        v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_radio);
>>       }
>>       kref_get(&dev->ref);
>> @@ -2222,7 +2235,7 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
>>       mutex_lock(&dev->lock);
>> -    v4l2_device_disconnect(&v4l2->v4l2_dev);
>> +    v4l2_device_disconnect(v4l2->v4l2_dev);
>>       em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
>> @@ -2238,14 +2251,15 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
>>                video_device_node_name(&v4l2->vbi_dev));
>>           video_unregister_device(&v4l2->vbi_dev);
>>       }
>> -    if (video_is_registered(&v4l2->vdev)) {
>> +    if (video_is_registered(v4l2->vdev)) {
>>           dev_info(&dev->intf->dev, "V4L2 device %s deregistered\n",
>> -             video_device_node_name(&v4l2->vdev));
>> -        video_unregister_device(&v4l2->vdev);
>> +             video_device_node_name(v4l2->vdev));
>> +        video_unregister_device(v4l2->vdev);
>>       }
>>       v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
>> -    v4l2_device_unregister(&v4l2->v4l2_dev);
>> +    v4l2_device_unregister(v4l2->v4l2_dev);
>> +    v4l2_device_put(v4l2->v4l2_dev);
>>       kref_put(&v4l2->ref, em28xx_free_v4l2);
>> @@ -2305,7 +2319,7 @@ static int em28xx_v4l2_close(struct file *filp)
>>               goto exit;
>>           /* Save some power by putting tuner to sleep */
>> -        v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
>> +        v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
>>           /* do this before setting alternate! */
>>           em28xx_set_mode(dev, EM28XX_SUSPEND);
>> @@ -2330,6 +2344,17 @@ static int em28xx_v4l2_close(struct file *filp)
>>       return 0;
>>   }
>> +void em28xx_vdev_release(struct video_device *vdev)
>> +{
>> +#ifdef CONFIG_MEDIA_CONTROLLER
>> +    int i;
>> +
>> +    for (i = 0; i < vdev->entity.num_pads; i++)
>> +        kfree(&vdev->entity.pads[i]);
>> +#endif
>> +    kfree(vdev);
>> +}
>> +
>>   static const struct v4l2_file_operations em28xx_v4l_fops = {
>>       .owner         = THIS_MODULE,
>>       .open          = em28xx_v4l2_open,
>> @@ -2387,7 +2412,7 @@ static const struct v4l2_ioctl_ops 
>> video_ioctl_ops = {
>>   static const struct video_device em28xx_video_template = {
>>       .fops        = &em28xx_v4l_fops,
>>       .ioctl_ops    = &video_ioctl_ops,
>> -    .release    = video_device_release_empty,
>> +    .release    = em28xx_vdev_release,
>>       .tvnorms    = V4L2_STD_ALL,
>>   };
>> @@ -2445,7 +2470,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
>>                    const char *type_name)
>>   {
>>       *vfd        = *template;
>> -    vfd->v4l2_dev    = &dev->v4l2->v4l2_dev;
>> +    vfd->v4l2_dev    = dev->v4l2->v4l2_dev;
>>       vfd->lock    = &dev->lock;
>>       if (dev->is_webcam)
>>           vfd->tvnorms = 0;
>> @@ -2459,7 +2484,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
>>   static void em28xx_tuner_setup(struct em28xx *dev, unsigned short 
>> tuner_addr)
>>   {
>>       struct em28xx_v4l2      *v4l2 = dev->v4l2;
>> -    struct v4l2_device      *v4l2_dev = &v4l2->v4l2_dev;
>> +    struct v4l2_device      *v4l2_dev = v4l2->v4l2_dev;
>>       struct tuner_setup      tun_setup;
>>       struct v4l2_frequency   f;
>> @@ -2517,6 +2542,11 @@ static void em28xx_tuner_setup(struct em28xx 
>> *dev, unsigned short tuner_addr)
>>       v4l2_device_call_all(v4l2_dev, 0, tuner, s_frequency, &f);
>>   }
>> +void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
>> +{
>> +    kfree(v4l2_dev);
>> +}
>> +
>>   static int em28xx_v4l2_init(struct em28xx *dev)
>>   {
>>       u8 val;
>> @@ -2541,26 +2571,35 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>       v4l2 = kzalloc(sizeof(*v4l2), GFP_KERNEL);
>>       if (!v4l2) {
>> -        mutex_unlock(&dev->lock);
>> -        return -ENOMEM;
>> +        ret = -ENOMEM;
>> +        goto v4l2_error;
>>       }
>> +
>>       kref_init(&v4l2->ref);
>>       v4l2->dev = dev;
>>       dev->v4l2 = v4l2;
>> +    v4l2->v4l2_dev = kzalloc(sizeof(*v4l2->v4l2_dev), GFP_KERNEL);
>> +    if (!v4l2->v4l2_dev) {
>> +        ret = -ENOMEM;
>> +        goto v4l2_dev_error;
>> +    }
>> +
>> +    v4l2->v4l2_dev->release = em28xx_v4l2_dev_release;
>> +
>>   #ifdef CONFIG_MEDIA_CONTROLLER
>> -    v4l2->v4l2_dev.mdev = dev->media_dev;
>> +    v4l2->v4l2_dev->mdev = dev->media_dev;
>>   #endif
>> -    ret = v4l2_device_register(&dev->intf->dev, &v4l2->v4l2_dev);
>> +    ret = v4l2_device_register(&dev->intf->dev, v4l2->v4l2_dev);
>>       if (ret < 0) {
>>           dev_err(&dev->intf->dev,
>>               "Call to v4l2_device_register() failed!\n");
>> -        goto err;
>> +        goto v4l2_device_register_error;
>>       }
>>       hdl = &v4l2->ctrl_handler;
>>       v4l2_ctrl_handler_init(hdl, 8);
>> -    v4l2->v4l2_dev.ctrl_handler = hdl;
>> +    v4l2->v4l2_dev->ctrl_handler = hdl;
>>       if (dev->is_webcam)
>>           v4l2->progressive = true;
>> @@ -2575,22 +2614,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>       /* request some modules */
>>       if (dev->has_msp34xx)
>> -        v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +        v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                       &dev->i2c_adap[dev->def_i2c_bus],
>>                       "msp3400", 0, msp3400_addrs);
>>       if (dev->board.decoder == EM28XX_SAA711X)
>> -        v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +        v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                       &dev->i2c_adap[dev->def_i2c_bus],
>>                       "saa7115_auto", 0, saa711x_addrs);
>>       if (dev->board.decoder == EM28XX_TVP5150)
>> -        v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +        v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                       &dev->i2c_adap[dev->def_i2c_bus],
>>                       "tvp5150", 0, tvp5150_addrs);
>>       if (dev->board.adecoder == EM28XX_TVAUDIO)
>> -        v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +        v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                       &dev->i2c_adap[dev->def_i2c_bus],
>>                       "tvaudio", dev->board.tvaudio_addr, NULL);
>> @@ -2601,13 +2640,13 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>           int has_demod = (dev->board.tda9887_conf & TDA9887_PRESENT);
>>           if (dev->board.radio.type)
>> -            v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +            v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                           &dev->i2c_adap[dev->def_i2c_bus],
>>                           "tuner", dev->board.radio_addr,
>>                           NULL);
> 
> Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
> check error prior to this change to allocating v4l2_dev. Now this has
> to be handled as a error leg.


I will add to all bellow.

> 
>>           if (has_demod)
>> -            v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +            v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                           &dev->i2c_adap[dev->def_i2c_bus],
>>                           "tuner", 0,
>>                           v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
> 
> Same here:
> 
> Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
> check error prior to this change to allocating v4l2_dev. Now this has
> to be handled as a error leg.
> 
>> @@ -2616,7 +2655,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>                   has_demod ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
>>               struct v4l2_subdev *sd;
>> -            sd = v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +            sd = v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                            &dev->i2c_adap[dev->def_i2c_bus],
>>                            "tuner", 0,
>>                            v4l2_i2c_tuner_addrs(type));
>> @@ -2624,7 +2663,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>               if (sd)
>>                   tuner_addr = v4l2_i2c_subdev_addr(sd);
> 
> Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
> check error prior to this change to allocating v4l2_dev. Now this has
> to be handled as a error leg.
> 
>>           } else {
>> -            v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +            v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                           &dev->i2c_adap[dev->def_i2c_bus],
>>                           "tuner", tuner_addr, NULL);
> 
> Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
> check error prior to this change to allocating v4l2_dev. Now this has
> to be handled as a error leg.
> 
>>           }
>> @@ -2686,7 +2725,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>       /* set default norm */
>>       v4l2->norm = V4L2_STD_PAL;
>> -    v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>> +    v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>>       v4l2->interlaced_fieldmode = EM28XX_INTERLACED_DEFAULT;
>>       /* Analog specific initialization */
>> @@ -2756,40 +2795,45 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>           goto unregister_dev;
>>       /* allocate and fill video video_device struct */
>> -    em28xx_vdev_init(dev, &v4l2->vdev, &em28xx_video_template, "video");
>> +    v4l2->vdev = kzalloc(sizeof(*v4l2->vdev), GFP_KERNEL);
>> +    if (!v4l2->vdev) {
>> +        ret = -ENOMEM;
>> +        goto unregister_dev;
>> +    }
>> +
>> +    em28xx_vdev_init(dev, v4l2->vdev, &em28xx_video_template, "video");
>>       mutex_init(&v4l2->vb_queue_lock);
>>       mutex_init(&v4l2->vb_vbi_queue_lock);
>> -    v4l2->vdev.queue = &v4l2->vb_vidq;
>> -    v4l2->vdev.queue->lock = &v4l2->vb_queue_lock;
>> -    v4l2->vdev.device_caps = V4L2_CAP_READWRITE | 
>> V4L2_CAP_VIDEO_CAPTURE |
>> +    v4l2->vdev->queue = &v4l2->vb_vidq;
>> +    v4l2->vdev->queue->lock = &v4l2->vb_queue_lock;
>> +    v4l2->vdev->device_caps = V4L2_CAP_READWRITE | 
>> V4L2_CAP_VIDEO_CAPTURE |
>>                    V4L2_CAP_STREAMING;
>>       if (dev->int_audio_type != EM28XX_INT_AUDIO_NONE)
>> -        v4l2->vdev.device_caps |= V4L2_CAP_AUDIO;
>> +        v4l2->vdev->device_caps |= V4L2_CAP_AUDIO;
>>       if (dev->tuner_type != TUNER_ABSENT)
>> -        v4l2->vdev.device_caps |= V4L2_CAP_TUNER;
>> -
>> +        v4l2->vdev->device_caps |= V4L2_CAP_TUNER;
>>       /* disable inapplicable ioctls */
>>       if (dev->is_webcam) {
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_QUERYSTD);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_STD);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_STD);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_QUERYSTD);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_STD);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_STD);
>>       } else {
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_PARM);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_PARM);
>>       }
>>       if (dev->tuner_type == TUNER_ABSENT) {
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_TUNER);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_TUNER);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_FREQUENCY);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_FREQUENCY);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_TUNER);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_TUNER);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_FREQUENCY);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_FREQUENCY);
>>       }
>>       if (dev->int_audio_type == EM28XX_INT_AUDIO_NONE) {
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_AUDIO);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_AUDIO);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_AUDIO);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_AUDIO);
>>       }
>>       /* register v4l2 video video_device */
>> -    ret = video_register_device(&v4l2->vdev, VFL_TYPE_VIDEO,
>> +    ret = video_register_device(v4l2->vdev, VFL_TYPE_VIDEO,
>>                       video_nr[dev->devno]);
>>       if (ret) {
>>           dev_err(&dev->intf->dev,
>> @@ -2863,7 +2907,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>       dev_info(&dev->intf->dev,
>>            "V4L2 video device registered as %s\n",
>> -         video_device_node_name(&v4l2->vdev));
>> +         video_device_node_name(v4l2->vdev));
>>       if (video_is_registered(&v4l2->vbi_dev))
>>           dev_info(&dev->intf->dev,
>> @@ -2871,7 +2915,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>                video_device_node_name(&v4l2->vbi_dev));
>>       /* Save some power by putting tuner to sleep */
>> -    v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
>> +    v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
>>       /* initialize videobuf2 stuff */
>>       em28xx_vb2_setup(dev);
>> @@ -2897,18 +2941,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>                video_device_node_name(&v4l2->vbi_dev));
>>           video_unregister_device(&v4l2->vbi_dev);
>>       }
>> -    if (video_is_registered(&v4l2->vdev)) {
>> +    if (video_is_registered(v4l2->vdev)) {
>>           dev_info(&dev->intf->dev,
>>                "V4L2 device %s deregistered\n",
>> -             video_device_node_name(&v4l2->vdev));
>> -        video_unregister_device(&v4l2->vdev);
>> +             video_device_node_name(v4l2->vdev));
>> +        video_unregister_device(v4l2->vdev);
>>       }
>>       v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
>> -    v4l2_device_unregister(&v4l2->v4l2_dev);
>> -err:
>> +    v4l2_device_unregister(v4l2->v4l2_dev);
>> +
>> +v4l2_device_register_error:
>> +    v4l2_device_put(v4l2->v4l2_dev);
>> +v4l2_dev_error:
>>       dev->v4l2 = NULL;
>>       kref_put(&v4l2->ref, em28xx_free_v4l2);
>> +v4l2_error:
>>       mutex_unlock(&dev->lock);
>>       return ret;
>>   }
>> diff --git a/drivers/media/usb/em28xx/em28xx.h 
>> b/drivers/media/usb/em28xx/em28xx.h
>> index 6648e11f1271..dbcc297b5a0d 100644
>> --- a/drivers/media/usb/em28xx/em28xx.h
>> +++ b/drivers/media/usb/em28xx/em28xx.h
>> @@ -552,10 +552,10 @@ struct em28xx_v4l2 {
>>       struct kref ref;
>>       struct em28xx *dev;
>> -    struct v4l2_device v4l2_dev;
>> +    struct v4l2_device *v4l2_dev;
>>       struct v4l2_ctrl_handler ctrl_handler;
>> -    struct video_device vdev;
>> +    struct video_device *vdev;
>>       struct video_device vbi_dev;
>>       struct video_device radio_dev;
>> @@ -601,7 +601,7 @@ struct em28xx_v4l2 {
>>       unsigned int field_count;
>>   #ifdef CONFIG_MEDIA_CONTROLLER
>> -    struct media_pad video_pad, vbi_pad;
>> +    struct media_pad *video_pad, vbi_pad;
>>       struct media_entity *decoder;
>>   #endif
>>   };
>>
> 
> thanks,
> -- Shuah

Thanks,
---
Igor Matheus Andrade Torrente

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH] media: em28xx: Fix race condition between open and init function
@ 2021-04-09 13:40     ` Igor Torrente
  0 siblings, 0 replies; 9+ messages in thread
From: Igor Torrente @ 2021-04-09 13:40 UTC (permalink / raw)
  To: Shuah Khan, mchehab
  Cc: linux-media, linux-kernel-mentees, linux-kernel,
	syzbot+b2391895514ed9ef4a8e



On 4/8/21 2:37 PM, Shuah Khan wrote:
> On 4/8/21 6:10 AM, Igor Matheus Andrade Torrente wrote:
>> Fixes a race condition - for lack of a more precise term - between
>> em28xx_v4l2_open and em28xx_v4l2_init, by detaching the v4l2_dev,
>> media_pad and vdev structs from the em28xx_v4l2, and managing the
>> lifetime of those objects more dynamicaly.
>>
>> The race happens when a thread[1] - containing the em28xx_v4l2_init()
>> code - calls the v4l2_mc_create_media_graph(), and it return a error,
>> if a thread[2] - running v4l2_open() - pass the verification point
>> and reaches the em28xx_v4l2_open() before the thread[1] finishes
>> the v4l2 subsystem deregistration, thread[1] will free all resources
>> before the em28xx_v4l2_open() can process their things,
>> because the em28xx_v4l2_init() has the dev->lock. And all this lead
>> the thread[2] to cause a user-after-free.
>>
> 
> Have you tried this patch with em28xx device? You will have to take into
> account the dependencies between the subdevs using the v4l2_dev.
> 

No, I didn't because I don't have the device.
I was using the syzbot .c that produces this use-after-free.
I will try to modify the .c to test a complete initialization.

Actually, I forgot to put RFC alongside [PATCH].

> Also try rmmod invidual drivers - what happens if you were to rmmod a
> subdev driver? With v4l2_dev is not embedded in v4l2, this could open
> up memory leaks or user-after-frees.
> 

OK. Let me see what I can do.

>> Reported-and-tested-by: 
>> syzbot+b2391895514ed9ef4a8e@syzkaller.appspotmail.com
>> Signed-off-by: Igor Matheus Andrade Torrente <igormtorrente@gmail.com>
>> ---
>>   drivers/media/usb/em28xx/em28xx-camera.c |   4 +-
>>   drivers/media/usb/em28xx/em28xx-video.c  | 188 ++++++++++++++---------
>>   drivers/media/usb/em28xx/em28xx.h        |   6 +-
>>   3 files changed, 123 insertions(+), 75 deletions(-)
>>
>> diff --git a/drivers/media/usb/em28xx/em28xx-camera.c 
>> b/drivers/media/usb/em28xx/em28xx-camera.c
>> index d1e66b503f4d..436c5a8cbbb6 100644
>> --- a/drivers/media/usb/em28xx/em28xx-camera.c
>> +++ b/drivers/media/usb/em28xx/em28xx-camera.c
>> @@ -340,7 +340,7 @@ int em28xx_init_camera(struct em28xx *dev)
>>           v4l2->sensor_xtal = 4300000;
>>           pdata.xtal = v4l2->sensor_xtal;
>>           if (NULL ==
>> -            v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
>> +            v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
>>                             &mt9v011_info, NULL))
>>               return -ENODEV;
>>           v4l2->vinmode = EM28XX_VINMODE_RGB8_GRBG;
>> @@ -394,7 +394,7 @@ int em28xx_init_camera(struct em28xx *dev)
>>           v4l2->sensor_yres = 480;
>>           subdev =
>> -             v4l2_i2c_new_subdev_board(&v4l2->v4l2_dev, adap,
>> +             v4l2_i2c_new_subdev_board(v4l2->v4l2_dev, adap,
>>                              &ov2640_info, NULL);
>>           if (!subdev)
>>               return -ENODEV;
>> diff --git a/drivers/media/usb/em28xx/em28xx-video.c 
>> b/drivers/media/usb/em28xx/em28xx-video.c
>> index 6b84c3413e83..e1febb2bf06b 100644
>> --- a/drivers/media/usb/em28xx/em28xx-video.c
>> +++ b/drivers/media/usb/em28xx/em28xx-video.c
>> @@ -184,7 +184,7 @@ static int em28xx_vbi_supported(struct em28xx *dev)
>>    */
>>   static void em28xx_wake_i2c(struct em28xx *dev)
>>   {
>> -    struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
>> +    struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
>>       v4l2_device_call_all(v4l2_dev, 0, core,  reset, 0);
>>       v4l2_device_call_all(v4l2_dev, 0, video, s_routing,
>> @@ -974,9 +974,17 @@ static void em28xx_v4l2_create_entities(struct 
>> em28xx *dev)
>>       struct em28xx_v4l2 *v4l2 = dev->v4l2;
>>       int ret, i;
>> +    v4l2->video_pad = kzalloc(sizeof(*v4l2->video_pad), GFP_KERNEL);
>> +    if (!v4l2->video_pad) {
>> +        dev_err(&dev->intf->dev,
>> +            "failed to allocate video pad memory!\n");
>> +        v4l2->vdev->entity.num_pads = 0;
>> +        return;
>> +    }
>> +
>>       /* Initialize Video, VBI and Radio pads */
>> -    v4l2->video_pad.flags = MEDIA_PAD_FL_SINK;
>> -    ret = media_entity_pads_init(&v4l2->vdev.entity, 1, 
>> &v4l2->video_pad);
>> +    v4l2->video_pad->flags = MEDIA_PAD_FL_SINK;
>> +    ret = media_entity_pads_init(&v4l2->vdev->entity, 1, 
>> v4l2->video_pad);
>>       if (ret < 0)
>>           dev_err(&dev->intf->dev,
>>               "failed to initialize video media entity!\n");
>> @@ -1132,11 +1140,11 @@ int em28xx_start_analog_streaming(struct 
>> vb2_queue *vq, unsigned int count)
>>               f.type = V4L2_TUNER_RADIO;
>>           else
>>               f.type = V4L2_TUNER_ANALOG_TV;
>> -        v4l2_device_call_all(&v4l2->v4l2_dev,
>> +        v4l2_device_call_all(v4l2->v4l2_dev,
>>                        0, tuner, s_frequency, &f);
>>           /* Enable video stream at TV decoder */
>> -        v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 1);
>> +        v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 1);
>>       }
>>       v4l2->streaming_users++;
>> @@ -1157,7 +1165,7 @@ static void em28xx_stop_streaming(struct 
>> vb2_queue *vq)
>>       if (v4l2->streaming_users-- == 1) {
>>           /* Disable video stream at TV decoder */
>> -        v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
>> +        v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
>>           /* Last active user, so shutdown all the URBS */
>>           em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
>> @@ -1192,7 +1200,7 @@ void em28xx_stop_vbi_streaming(struct vb2_queue 
>> *vq)
>>       if (v4l2->streaming_users-- == 1) {
>>           /* Disable video stream at TV decoder */
>> -        v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_stream, 0);
>> +        v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_stream, 0);
>>           /* Last active user, so shutdown all the URBS */
>>           em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
>> @@ -1286,7 +1294,7 @@ static int em28xx_vb2_setup(struct em28xx *dev)
>>   static void video_mux(struct em28xx *dev, int index)
>>   {
>> -    struct v4l2_device *v4l2_dev = &dev->v4l2->v4l2_dev;
>> +    struct v4l2_device *v4l2_dev = dev->v4l2->v4l2_dev;
>>       dev->ctl_input = index;
>>       dev->ctl_ainput = INPUT(index)->amux;
>> @@ -1565,7 +1573,7 @@ static int vidioc_querystd(struct file *file, 
>> void *priv, v4l2_std_id *norm)
>>   {
>>       struct em28xx *dev = video_drvdata(file);
>> -    v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, video, querystd, 
>> norm);
>> +    v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, video, querystd, norm);
>>       return 0;
>>   }
>> @@ -1596,7 +1604,7 @@ static int vidioc_s_std(struct file *file, void 
>> *priv, v4l2_std_id norm)
>>                 &v4l2->hscale, &v4l2->vscale);
>>       em28xx_resolution_set(dev);
>> -    v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>> +    v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>>       return 0;
>>   }
>> @@ -1616,7 +1624,7 @@ static int vidioc_g_parm(struct file *file, void 
>> *priv,
>>       p->parm.capture.readbuffers = EM28XX_MIN_BUF;
>>       p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
>>       if (dev->is_webcam) {
>> -        rc = v4l2_device_call_until_err(&v4l2->v4l2_dev, 0,
>> +        rc = v4l2_device_call_until_err(v4l2->v4l2_dev, 0,
>>                           video, g_frame_interval, &ival);
>>           if (!rc)
>>               p->parm.capture.timeperframe = ival.interval;
>> @@ -1648,7 +1656,7 @@ static int vidioc_s_parm(struct file *file, void 
>> *priv,
>>       memset(&p->parm, 0, sizeof(p->parm));
>>       p->parm.capture.readbuffers = EM28XX_MIN_BUF;
>>       p->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
>> -    rc = v4l2_device_call_until_err(&dev->v4l2->v4l2_dev, 0,
>> +    rc = v4l2_device_call_until_err(dev->v4l2->v4l2_dev, 0,
>>                       video, s_frame_interval, &ival);
>>       if (!rc)
>>           p->parm.capture.timeperframe = ival.interval;
>> @@ -1675,7 +1683,7 @@ static int vidioc_enum_input(struct file *file, 
>> void *priv,
>>       if (INPUT(n)->type == EM28XX_VMUX_TELEVISION)
>>           i->type = V4L2_INPUT_TYPE_TUNER;
>> -    i->std = dev->v4l2->vdev.tvnorms;
>> +    i->std = dev->v4l2->vdev->tvnorms;
>>       /* webcams do not have the STD API */
>>       if (dev->is_webcam)
>>           i->capabilities = 0;
>> @@ -1839,7 +1847,7 @@ static int vidioc_g_tuner(struct file *file, 
>> void *priv,
>>       strscpy(t->name, "Tuner", sizeof(t->name));
>> -    v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>> +    v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>>       return 0;
>>   }
>> @@ -1851,7 +1859,7 @@ static int vidioc_s_tuner(struct file *file, 
>> void *priv,
>>       if (t->index != 0)
>>           return -EINVAL;
>> -    v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>> +    v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>>       return 0;
>>   }
>> @@ -1878,8 +1886,8 @@ static int vidioc_s_frequency(struct file *file, 
>> void *priv,
>>       if (f->tuner != 0)
>>           return -EINVAL;
>> -    v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_frequency, f);
>> -    v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, g_frequency, 
>> &new_freq);
>> +    v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_frequency, f);
>> +    v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, g_frequency, 
>> &new_freq);
>>       v4l2->frequency = new_freq.frequency;
>>       return 0;
>> @@ -1897,7 +1905,7 @@ static int vidioc_g_chip_info(struct file *file, 
>> void *priv,
>>           strscpy(chip->name, "ac97", sizeof(chip->name));
>>       else
>>           strscpy(chip->name,
>> -            dev->v4l2->v4l2_dev.name, sizeof(chip->name));
>> +            dev->v4l2->v4l2_dev->name, sizeof(chip->name));
>>       return 0;
>>   }
>> @@ -2095,7 +2103,7 @@ static int radio_g_tuner(struct file *file, void 
>> *priv,
>>       strscpy(t->name, "Radio", sizeof(t->name));
>> -    v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>> +    v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, g_tuner, t);
>>       return 0;
>>   }
>> @@ -2108,7 +2116,7 @@ static int radio_s_tuner(struct file *file, void 
>> *priv,
>>       if (t->index != 0)
>>           return -EINVAL;
>> -    v4l2_device_call_all(&dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>> +    v4l2_device_call_all(dev->v4l2->v4l2_dev, 0, tuner, s_tuner, t);
>>       return 0;
>>   }
>> @@ -2160,6 +2168,11 @@ static int em28xx_v4l2_open(struct file *filp)
>>       if (mutex_lock_interruptible(&dev->lock))
>>           return -ERESTARTSYS;
>> +    if (!dev->v4l2) {
>> +        mutex_unlock(&dev->lock);
>> +        return -ENODEV;
>> +    }
>> +
>>       ret = v4l2_fh_open(filp);
>>       if (ret) {
>>           dev_err(&dev->intf->dev,
>> @@ -2184,7 +2197,7 @@ static int em28xx_v4l2_open(struct file *filp)
>>       if (vdev->vfl_type == VFL_TYPE_RADIO) {
>>           em28xx_videodbg("video_open: setting radio device\n");
>> -        v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, s_radio);
>> +        v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, s_radio);
>>       }
>>       kref_get(&dev->ref);
>> @@ -2222,7 +2235,7 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
>>       mutex_lock(&dev->lock);
>> -    v4l2_device_disconnect(&v4l2->v4l2_dev);
>> +    v4l2_device_disconnect(v4l2->v4l2_dev);
>>       em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE);
>> @@ -2238,14 +2251,15 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
>>                video_device_node_name(&v4l2->vbi_dev));
>>           video_unregister_device(&v4l2->vbi_dev);
>>       }
>> -    if (video_is_registered(&v4l2->vdev)) {
>> +    if (video_is_registered(v4l2->vdev)) {
>>           dev_info(&dev->intf->dev, "V4L2 device %s deregistered\n",
>> -             video_device_node_name(&v4l2->vdev));
>> -        video_unregister_device(&v4l2->vdev);
>> +             video_device_node_name(v4l2->vdev));
>> +        video_unregister_device(v4l2->vdev);
>>       }
>>       v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
>> -    v4l2_device_unregister(&v4l2->v4l2_dev);
>> +    v4l2_device_unregister(v4l2->v4l2_dev);
>> +    v4l2_device_put(v4l2->v4l2_dev);
>>       kref_put(&v4l2->ref, em28xx_free_v4l2);
>> @@ -2305,7 +2319,7 @@ static int em28xx_v4l2_close(struct file *filp)
>>               goto exit;
>>           /* Save some power by putting tuner to sleep */
>> -        v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
>> +        v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
>>           /* do this before setting alternate! */
>>           em28xx_set_mode(dev, EM28XX_SUSPEND);
>> @@ -2330,6 +2344,17 @@ static int em28xx_v4l2_close(struct file *filp)
>>       return 0;
>>   }
>> +void em28xx_vdev_release(struct video_device *vdev)
>> +{
>> +#ifdef CONFIG_MEDIA_CONTROLLER
>> +    int i;
>> +
>> +    for (i = 0; i < vdev->entity.num_pads; i++)
>> +        kfree(&vdev->entity.pads[i]);
>> +#endif
>> +    kfree(vdev);
>> +}
>> +
>>   static const struct v4l2_file_operations em28xx_v4l_fops = {
>>       .owner         = THIS_MODULE,
>>       .open          = em28xx_v4l2_open,
>> @@ -2387,7 +2412,7 @@ static const struct v4l2_ioctl_ops 
>> video_ioctl_ops = {
>>   static const struct video_device em28xx_video_template = {
>>       .fops        = &em28xx_v4l_fops,
>>       .ioctl_ops    = &video_ioctl_ops,
>> -    .release    = video_device_release_empty,
>> +    .release    = em28xx_vdev_release,
>>       .tvnorms    = V4L2_STD_ALL,
>>   };
>> @@ -2445,7 +2470,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
>>                    const char *type_name)
>>   {
>>       *vfd        = *template;
>> -    vfd->v4l2_dev    = &dev->v4l2->v4l2_dev;
>> +    vfd->v4l2_dev    = dev->v4l2->v4l2_dev;
>>       vfd->lock    = &dev->lock;
>>       if (dev->is_webcam)
>>           vfd->tvnorms = 0;
>> @@ -2459,7 +2484,7 @@ static void em28xx_vdev_init(struct em28xx *dev,
>>   static void em28xx_tuner_setup(struct em28xx *dev, unsigned short 
>> tuner_addr)
>>   {
>>       struct em28xx_v4l2      *v4l2 = dev->v4l2;
>> -    struct v4l2_device      *v4l2_dev = &v4l2->v4l2_dev;
>> +    struct v4l2_device      *v4l2_dev = v4l2->v4l2_dev;
>>       struct tuner_setup      tun_setup;
>>       struct v4l2_frequency   f;
>> @@ -2517,6 +2542,11 @@ static void em28xx_tuner_setup(struct em28xx 
>> *dev, unsigned short tuner_addr)
>>       v4l2_device_call_all(v4l2_dev, 0, tuner, s_frequency, &f);
>>   }
>> +void em28xx_v4l2_dev_release(struct v4l2_device *v4l2_dev)
>> +{
>> +    kfree(v4l2_dev);
>> +}
>> +
>>   static int em28xx_v4l2_init(struct em28xx *dev)
>>   {
>>       u8 val;
>> @@ -2541,26 +2571,35 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>       v4l2 = kzalloc(sizeof(*v4l2), GFP_KERNEL);
>>       if (!v4l2) {
>> -        mutex_unlock(&dev->lock);
>> -        return -ENOMEM;
>> +        ret = -ENOMEM;
>> +        goto v4l2_error;
>>       }
>> +
>>       kref_init(&v4l2->ref);
>>       v4l2->dev = dev;
>>       dev->v4l2 = v4l2;
>> +    v4l2->v4l2_dev = kzalloc(sizeof(*v4l2->v4l2_dev), GFP_KERNEL);
>> +    if (!v4l2->v4l2_dev) {
>> +        ret = -ENOMEM;
>> +        goto v4l2_dev_error;
>> +    }
>> +
>> +    v4l2->v4l2_dev->release = em28xx_v4l2_dev_release;
>> +
>>   #ifdef CONFIG_MEDIA_CONTROLLER
>> -    v4l2->v4l2_dev.mdev = dev->media_dev;
>> +    v4l2->v4l2_dev->mdev = dev->media_dev;
>>   #endif
>> -    ret = v4l2_device_register(&dev->intf->dev, &v4l2->v4l2_dev);
>> +    ret = v4l2_device_register(&dev->intf->dev, v4l2->v4l2_dev);
>>       if (ret < 0) {
>>           dev_err(&dev->intf->dev,
>>               "Call to v4l2_device_register() failed!\n");
>> -        goto err;
>> +        goto v4l2_device_register_error;
>>       }
>>       hdl = &v4l2->ctrl_handler;
>>       v4l2_ctrl_handler_init(hdl, 8);
>> -    v4l2->v4l2_dev.ctrl_handler = hdl;
>> +    v4l2->v4l2_dev->ctrl_handler = hdl;
>>       if (dev->is_webcam)
>>           v4l2->progressive = true;
>> @@ -2575,22 +2614,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>       /* request some modules */
>>       if (dev->has_msp34xx)
>> -        v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +        v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                       &dev->i2c_adap[dev->def_i2c_bus],
>>                       "msp3400", 0, msp3400_addrs);
>>       if (dev->board.decoder == EM28XX_SAA711X)
>> -        v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +        v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                       &dev->i2c_adap[dev->def_i2c_bus],
>>                       "saa7115_auto", 0, saa711x_addrs);
>>       if (dev->board.decoder == EM28XX_TVP5150)
>> -        v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +        v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                       &dev->i2c_adap[dev->def_i2c_bus],
>>                       "tvp5150", 0, tvp5150_addrs);
>>       if (dev->board.adecoder == EM28XX_TVAUDIO)
>> -        v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +        v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                       &dev->i2c_adap[dev->def_i2c_bus],
>>                       "tvaudio", dev->board.tvaudio_addr, NULL);
>> @@ -2601,13 +2640,13 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>           int has_demod = (dev->board.tda9887_conf & TDA9887_PRESENT);
>>           if (dev->board.radio.type)
>> -            v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +            v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                           &dev->i2c_adap[dev->def_i2c_bus],
>>                           "tuner", dev->board.radio_addr,
>>                           NULL);
> 
> Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
> check error prior to this change to allocating v4l2_dev. Now this has
> to be handled as a error leg.


I will add to all bellow.

> 
>>           if (has_demod)
>> -            v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +            v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                           &dev->i2c_adap[dev->def_i2c_bus],
>>                           "tuner", 0,
>>                           v4l2_i2c_tuner_addrs(ADDRS_DEMOD));
> 
> Same here:
> 
> Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
> check error prior to this change to allocating v4l2_dev. Now this has
> to be handled as a error leg.
> 
>> @@ -2616,7 +2655,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>                   has_demod ? ADDRS_TV_WITH_DEMOD : ADDRS_TV;
>>               struct v4l2_subdev *sd;
>> -            sd = v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +            sd = v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                            &dev->i2c_adap[dev->def_i2c_bus],
>>                            "tuner", 0,
>>                            v4l2_i2c_tuner_addrs(type));
>> @@ -2624,7 +2663,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>               if (sd)
>>                   tuner_addr = v4l2_i2c_subdev_addr(sd);
> 
> Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
> check error prior to this change to allocating v4l2_dev. Now this has
> to be handled as a error leg.
> 
>>           } else {
>> -            v4l2_i2c_new_subdev(&v4l2->v4l2_dev,
>> +            v4l2_i2c_new_subdev(v4l2->v4l2_dev,
>>                           &dev->i2c_adap[dev->def_i2c_bus],
>>                           "tuner", tuner_addr, NULL);
> 
> Add null check for v4l2_i2c_new_subdev() and error handling. It was okay
> check error prior to this change to allocating v4l2_dev. Now this has
> to be handled as a error leg.
> 
>>           }
>> @@ -2686,7 +2725,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>       /* set default norm */
>>       v4l2->norm = V4L2_STD_PAL;
>> -    v4l2_device_call_all(&v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>> +    v4l2_device_call_all(v4l2->v4l2_dev, 0, video, s_std, v4l2->norm);
>>       v4l2->interlaced_fieldmode = EM28XX_INTERLACED_DEFAULT;
>>       /* Analog specific initialization */
>> @@ -2756,40 +2795,45 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>           goto unregister_dev;
>>       /* allocate and fill video video_device struct */
>> -    em28xx_vdev_init(dev, &v4l2->vdev, &em28xx_video_template, "video");
>> +    v4l2->vdev = kzalloc(sizeof(*v4l2->vdev), GFP_KERNEL);
>> +    if (!v4l2->vdev) {
>> +        ret = -ENOMEM;
>> +        goto unregister_dev;
>> +    }
>> +
>> +    em28xx_vdev_init(dev, v4l2->vdev, &em28xx_video_template, "video");
>>       mutex_init(&v4l2->vb_queue_lock);
>>       mutex_init(&v4l2->vb_vbi_queue_lock);
>> -    v4l2->vdev.queue = &v4l2->vb_vidq;
>> -    v4l2->vdev.queue->lock = &v4l2->vb_queue_lock;
>> -    v4l2->vdev.device_caps = V4L2_CAP_READWRITE | 
>> V4L2_CAP_VIDEO_CAPTURE |
>> +    v4l2->vdev->queue = &v4l2->vb_vidq;
>> +    v4l2->vdev->queue->lock = &v4l2->vb_queue_lock;
>> +    v4l2->vdev->device_caps = V4L2_CAP_READWRITE | 
>> V4L2_CAP_VIDEO_CAPTURE |
>>                    V4L2_CAP_STREAMING;
>>       if (dev->int_audio_type != EM28XX_INT_AUDIO_NONE)
>> -        v4l2->vdev.device_caps |= V4L2_CAP_AUDIO;
>> +        v4l2->vdev->device_caps |= V4L2_CAP_AUDIO;
>>       if (dev->tuner_type != TUNER_ABSENT)
>> -        v4l2->vdev.device_caps |= V4L2_CAP_TUNER;
>> -
>> +        v4l2->vdev->device_caps |= V4L2_CAP_TUNER;
>>       /* disable inapplicable ioctls */
>>       if (dev->is_webcam) {
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_QUERYSTD);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_STD);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_STD);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_QUERYSTD);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_STD);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_STD);
>>       } else {
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_PARM);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_PARM);
>>       }
>>       if (dev->tuner_type == TUNER_ABSENT) {
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_TUNER);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_TUNER);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_FREQUENCY);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_FREQUENCY);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_TUNER);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_TUNER);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_FREQUENCY);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_FREQUENCY);
>>       }
>>       if (dev->int_audio_type == EM28XX_INT_AUDIO_NONE) {
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_G_AUDIO);
>> -        v4l2_disable_ioctl(&v4l2->vdev, VIDIOC_S_AUDIO);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_G_AUDIO);
>> +        v4l2_disable_ioctl(v4l2->vdev, VIDIOC_S_AUDIO);
>>       }
>>       /* register v4l2 video video_device */
>> -    ret = video_register_device(&v4l2->vdev, VFL_TYPE_VIDEO,
>> +    ret = video_register_device(v4l2->vdev, VFL_TYPE_VIDEO,
>>                       video_nr[dev->devno]);
>>       if (ret) {
>>           dev_err(&dev->intf->dev,
>> @@ -2863,7 +2907,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>       dev_info(&dev->intf->dev,
>>            "V4L2 video device registered as %s\n",
>> -         video_device_node_name(&v4l2->vdev));
>> +         video_device_node_name(v4l2->vdev));
>>       if (video_is_registered(&v4l2->vbi_dev))
>>           dev_info(&dev->intf->dev,
>> @@ -2871,7 +2915,7 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>                video_device_node_name(&v4l2->vbi_dev));
>>       /* Save some power by putting tuner to sleep */
>> -    v4l2_device_call_all(&v4l2->v4l2_dev, 0, tuner, standby);
>> +    v4l2_device_call_all(v4l2->v4l2_dev, 0, tuner, standby);
>>       /* initialize videobuf2 stuff */
>>       em28xx_vb2_setup(dev);
>> @@ -2897,18 +2941,22 @@ static int em28xx_v4l2_init(struct em28xx *dev)
>>                video_device_node_name(&v4l2->vbi_dev));
>>           video_unregister_device(&v4l2->vbi_dev);
>>       }
>> -    if (video_is_registered(&v4l2->vdev)) {
>> +    if (video_is_registered(v4l2->vdev)) {
>>           dev_info(&dev->intf->dev,
>>                "V4L2 device %s deregistered\n",
>> -             video_device_node_name(&v4l2->vdev));
>> -        video_unregister_device(&v4l2->vdev);
>> +             video_device_node_name(v4l2->vdev));
>> +        video_unregister_device(v4l2->vdev);
>>       }
>>       v4l2_ctrl_handler_free(&v4l2->ctrl_handler);
>> -    v4l2_device_unregister(&v4l2->v4l2_dev);
>> -err:
>> +    v4l2_device_unregister(v4l2->v4l2_dev);
>> +
>> +v4l2_device_register_error:
>> +    v4l2_device_put(v4l2->v4l2_dev);
>> +v4l2_dev_error:
>>       dev->v4l2 = NULL;
>>       kref_put(&v4l2->ref, em28xx_free_v4l2);
>> +v4l2_error:
>>       mutex_unlock(&dev->lock);
>>       return ret;
>>   }
>> diff --git a/drivers/media/usb/em28xx/em28xx.h 
>> b/drivers/media/usb/em28xx/em28xx.h
>> index 6648e11f1271..dbcc297b5a0d 100644
>> --- a/drivers/media/usb/em28xx/em28xx.h
>> +++ b/drivers/media/usb/em28xx/em28xx.h
>> @@ -552,10 +552,10 @@ struct em28xx_v4l2 {
>>       struct kref ref;
>>       struct em28xx *dev;
>> -    struct v4l2_device v4l2_dev;
>> +    struct v4l2_device *v4l2_dev;
>>       struct v4l2_ctrl_handler ctrl_handler;
>> -    struct video_device vdev;
>> +    struct video_device *vdev;
>>       struct video_device vbi_dev;
>>       struct video_device radio_dev;
>> @@ -601,7 +601,7 @@ struct em28xx_v4l2 {
>>       unsigned int field_count;
>>   #ifdef CONFIG_MEDIA_CONTROLLER
>> -    struct media_pad video_pad, vbi_pad;
>> +    struct media_pad *video_pad, vbi_pad;
>>       struct media_entity *decoder;
>>   #endif
>>   };
>>
> 
> thanks,
> -- Shuah

Thanks,
---
Igor Matheus Andrade Torrente
_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2021-04-09 13:40 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-04-08 12:10 [PATCH] media: em28xx: Fix race condition between open and init function Igor Matheus Andrade Torrente
2021-04-08 12:10 ` Igor Matheus Andrade Torrente
2021-04-08 15:38 ` kernel test robot
2021-04-08 15:38   ` kernel test robot
2021-04-08 15:38   ` kernel test robot
2021-04-08 17:37 ` Shuah Khan
2021-04-08 17:37   ` Shuah Khan
2021-04-09 13:40   ` Igor Torrente
2021-04-09 13:40     ` Igor Torrente

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.