[PATCH] media: em28xx: fix memory leak in em28xx_init_dev

[Dongliang Mu]

In the em28xx_init_rev, if em28xx_audio_setup fails, this function fails
to deallocate the media_dev allocated in the em28xx_media_device_init.

Fix this by adding em28xx_unregister_media_device to free media_dev.

BTW, this patch is tested in my local syzkaller instance, and it can
prevent the memory leak from occurring again.

CC: Pavel Skripkin <paskripkin@xxxxxxxxx>
Fixes: 37ecc7b1278f ("[media] em28xx: add media controller support")
Signed-off-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
---
 drivers/media/usb/em28xx/em28xx-cards.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index c1e0dccb7408..fca68939ca50 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -3625,8 +3625,10 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
 
 	if (dev->is_audio_only) {
 		retval = em28xx_audio_setup(dev);
-		if (retval)
-			return -ENODEV;
+		if (retval) {
+			retval = -ENODEV;
+			goto err_deinit_media;
+		}
 		em28xx_init_extension(dev);
 
 		return 0;
@@ -3645,7 +3647,7 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
 		dev_err(&dev->intf->dev,
 			"%s: em28xx_i2c_register bus 0 - error [%d]!\n",
 		       __func__, retval);
-		return retval;
+		goto err_deinit_media;
 	}
 
 	/* register i2c bus 1 */
@@ -3661,9 +3663,7 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
 				"%s: em28xx_i2c_register bus 1 - error [%d]!\n",
 				__func__, retval);
 
-			em28xx_i2c_unregister(dev, 0);
-
-			return retval;
+			goto err_unreg_i2c;
 		}
 	}
 
@@ -3671,6 +3671,13 @@ static int em28xx_init_dev(struct em28xx *dev, struct usb_device *udev,
 	em28xx_card_setup(dev);
 
 	return 0;
+
+
+err_unreg_i2c:
+	em28xx_i2c_unregister(dev, 0);
+err_deinit_media:
+	em28xx_unregister_media_device(dev);
+	return retval;
 }
 
 static int em28xx_duplicate_dev(struct em28xx *dev)
-- 
2.25.1