lkml.org 
[lkml]   [2021]   [Jul]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] media: em28xx: add missing em28xx_close_extension
Date
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.

Fixes: 1a23f81b7dc3 ("V4L/DVB (9979): em28xx: move usb probe code to a proper place")
Reported-and-tested-by: syzbot+a6969ef522a36d3344c9@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---

Changes in v2:
Previous patch was completely broken. I've done some debugging
again and found true root case of the reported bug.

---
drivers/media/usb/em28xx/em28xx-cards.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index c1e0dccb7408..d56b040e1bd7 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -4139,8 +4139,10 @@ static void em28xx_usb_disconnect(struct usb_interface *intf)

em28xx_close_extension(dev);

- if (dev->dev_next)
+ if (dev->dev_next) {
em28xx_release_resources(dev->dev_next);
+ em28xx_close_extension(dev->dev_next);
+ }
em28xx_release_resources(dev);

if (dev->dev_next) {
--
2.32.0
\
 
 \ /
  Last update: 2021-07-21 21:44    [W:0.061 / U:0.168 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site