media: em28xx: fix memory leak in em28xx_init_dev

stable inclusion
from stable-v5.10.94
commit 0ff0ae69d27cfeb463b4452b74cebc52bdbd71e6
bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0ff0ae69d27cfeb463b4452b74cebc52bdbd71e6

--------------------------------

[ Upstream commit 22be5a10 ]

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@gmail.com>
Fixes: 37ecc7b1 ("[media] em28xx: add media controller support")
Signed-off-by: NDongliang Mu <mudongliangabcd@gmail.com>
Reported-by: Nsyzkaller <syzkaller@googlegroups.com>
Signed-off-by: NHans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/media/usb/em28xx/em28xx-cards.c

@@ -3575,8 +3575,10 @@ 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;
@@ -3595,7 +3597,7 @@ 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 */
@@ -3611,9 +3613,7 @@ 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;
 		}
 	}
 
@@ -3621,6 +3621,12 @@ 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)