Messages in this thread Patch in this message | | | From | Pavel Skripkin <> | Subject | [PATCH v2] media: em28xx: add missing em28xx_close_extension | Date | Wed, 21 Jul 2021 22:43:07 +0300 |
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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
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