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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Johan Hovold <johan@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Sasha Levin <sashal@kernel.org>, linux-usb@vger.kernel.org
Subject: [PATCH AUTOSEL 4.9 216/251] USB: usb-skeleton: fix use-after-free after driver unbind
Date:   Thu, 16 Jan 2020 12:36:05 -0500
Message-Id: <20200116173641.22137-176-sashal@kernel.org>
In-Reply-To: <20200116173641.22137-1-sashal@kernel.org>
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From: Johan Hovold <johan@kernel.org>

[ Upstream commit 6353001852776e7eeaab4da78922d4c6f2b076af ]

The driver failed to stop its read URB on disconnect, something which
could lead to a use-after-free in the completion handler after driver
unbind in case the character device has been closed.

Fixes: e7389cc9a7ff ("USB: skel_read really sucks royally")
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191009170944.30057-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/usb/usb-skeleton.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c
index f24374486623..1e6146f70cc7 100644
--- a/drivers/usb/usb-skeleton.c
+++ b/drivers/usb/usb-skeleton.c
@@ -584,6 +584,7 @@ static void skel_disconnect(struct usb_interface *interface)
 	dev->disconnected = 1;
 	mutex_unlock(&dev->io_mutex);
 
+	usb_kill_urb(dev->bulk_in_urb);
 	usb_kill_anchored_urbs(&dev->submitted);
 
 	/* decrement our usage count */
-- 
2.20.1