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From:   Johan Hovold <johan@kernel.org>
To:     Stefan Schmidt <stefan@datenfreihafen.org>
Cc:     Alexander Aring <alex.aring@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        linux-wpan@vger.kernel.org, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, andreyknvl@google.com,
        syzkaller-bugs@googlegroups.com, Johan Hovold <johan@kernel.org>,
        stable <stable@vger.kernel.org>,
        syzbot+f4509a9138a1472e7e80@syzkaller.appspotmail.com
Subject: [PATCH] ieee802154: atusb: fix use-after-free at disconnect
Date:   Thu, 19 Sep 2019 14:12:34 +0200
Message-Id: <20190919121234.30620-1-johan@kernel.org>
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Sender: linux-kernel-owner@vger.kernel.org
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The disconnect callback was accessing the hardware-descriptor private
data after having having freed it.

Fixes: 7490b008d123 ("ieee802154: add support for atusb transceiver")
Cc: stable <stable@vger.kernel.org>     # 4.2
Cc: Alexander Aring <alex.aring@gmail.com>
Reported-by: syzbot+f4509a9138a1472e7e80@syzkaller.appspotmail.com
Signed-off-by: Johan Hovold <johan@kernel.org>
---

#syz test: https://github.com/google/kasan.git f0df5c1b

 drivers/net/ieee802154/atusb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ieee802154/atusb.c b/drivers/net/ieee802154/atusb.c
index ceddb424f887..0dd0ba915ab9 100644
--- a/drivers/net/ieee802154/atusb.c
+++ b/drivers/net/ieee802154/atusb.c
@@ -1137,10 +1137,11 @@ static void atusb_disconnect(struct usb_interface *interface)
 
 	ieee802154_unregister_hw(atusb->hw);
 
+	usb_put_dev(atusb->usb_dev);
+
 	ieee802154_free_hw(atusb->hw);
 
 	usb_set_intfdata(interface, NULL);
-	usb_put_dev(atusb->usb_dev);
 
 	pr_debug("%s done\n", __func__);
 }
-- 
2.23.0