Linux-USB Archive on lore.kernel.org
 help / color / Atom feed
From: Johan Hovold <johan@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org, Keith Packard <keithp@keithp.com>,
	Juergen Stuber <starblue@users.sourceforge.net>,
	Johan Hovold <johan@kernel.org>, stable <stable@vger.kernel.org>
Subject: [PATCH 4/5] USB: legousbtower: fix use-after-free on release
Date: Wed,  9 Oct 2019 17:38:47 +0200
Message-ID: <20191009153848.8664-5-johan@kernel.org> (raw)
In-Reply-To: <20191009153848.8664-1-johan@kernel.org>

The driver was accessing its struct usb_device in its release()
callback without holding a reference. This would lead to a
use-after-free whenever the device was disconnected while the character
device was still open.

Fixes: fef526cae700 ("USB: legousbtower: remove custom debug macro")
Cc: stable <stable@vger.kernel.org>     # 3.12
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/misc/legousbtower.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index 44d6a3381804..9d4c52a7ebe0 100644
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -296,6 +296,7 @@ static inline void tower_delete (struct lego_usb_tower *dev)
 	kfree (dev->read_buffer);
 	kfree (dev->interrupt_in_buffer);
 	kfree (dev->interrupt_out_buffer);
+	usb_put_dev(dev->udev);
 	kfree (dev);
 }
 
@@ -810,7 +811,7 @@ static int tower_probe (struct usb_interface *interface, const struct usb_device
 
 	mutex_init(&dev->lock);
 
-	dev->udev = udev;
+	dev->udev = usb_get_dev(udev);
 	dev->open_count = 0;
 	dev->disconnected = 0;
 
-- 
2.23.0


  parent reply index

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-09 15:38 [PATCH 0/5] USB: misc: fix disconnect bugs Johan Hovold
2019-10-09 15:38 ` [PATCH 1/5] USB: adutux: fix use-after-free on release Johan Hovold
2019-10-09 15:38 ` [PATCH 2/5] USB: chaoskey: " Johan Hovold
2019-10-09 15:38 ` [PATCH 3/5] USB: ldusb: fix NULL-derefs on driver unbind Johan Hovold
2019-10-09 15:38 ` Johan Hovold [this message]
2019-10-09 15:38 ` [PATCH 5/5] USB: yurex: fix NULL-derefs on disconnect Johan Hovold
2019-10-10 11:05   ` Johan Hovold
2019-10-10 12:24     ` Greg Kroah-Hartman

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191009153848.8664-5-johan@kernel.org \
    --to=johan@kernel.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=keithp@keithp.com \
    --cc=linux-usb@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=starblue@users.sourceforge.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-USB Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-usb/0 linux-usb/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-usb linux-usb/ https://lore.kernel.org/linux-usb \
		linux-usb@vger.kernel.org
	public-inbox-index linux-usb

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-usb


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git