From 2c98b8a3458df03abdc6945bbef67ef91d181938 Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin@gmail.com>
Date: Thu, 29 Jul 2021 22:23:33 +0200
Subject: [PATCH] media: em28xx: add missing em28xx_close_extension
Git-commit: 2c98b8a3458df03abdc6945bbef67ef91d181938
Patch-mainline: v5.16-rc1
References: git-fixes

If em28xx dev has ->dev_next pointer, we need to delete ->dev_next list
node from em28xx_extension_devlist on disconnect to avoid UAF bugs and
corrupted list bugs, since driver frees this pointer on disconnect.

Reported-and-tested-by: syzbot+a6969ef522a36d3344c9@syzkaller.appspotmail.com

Fixes: 1a23f81b7dc3 ("V4L/DVB (9979): em28xx: move usb probe code to a proper place")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/media/usb/em28xx/em28xx-cards.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index c1e0dccb7408..948e22e29b42 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -4139,8 +4139,11 @@ static void em28xx_usb_disconnect(struct usb_interface *intf)
 
 	em28xx_close_extension(dev);
 
-	if (dev->dev_next)
+	if (dev->dev_next) {
+		em28xx_close_extension(dev->dev_next);
 		em28xx_release_resources(dev->dev_next);
+	}
+
 	em28xx_release_resources(dev);
 
 	if (dev->dev_next) {
-- 
2.26.2