From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4862YET1KgfMzafmedw64mZzU9yWBrpOn7eX8bsNO59ji9i23fW/VgFf0jGXAHljlAXuYIf ARC-Seal: i=1; a=rsa-sha256; t=1522346842; cv=none; d=google.com; s=arc-20160816; b=vEAqHAdMJR/xsRr9xwfiXLhPM6R1YKJAb9BemWMOwtJCQBUvBDGqDhcotG+lScEfW2 Wcr87hXGiCHnAbf9+6RC0vtyZzNXIT6Daxo0cHdbAjds8ROmNj87N58yQiACXw5IAqaP YkUXVdNJrnudXuMYuIHfxTCb4t600FwRxenURzoO0Cd6pZNujyrFc1YvWIxottUV664M 11sZ+RVgGqr/1FkKAHkiSOnTxOIptSkA+YjD3XLky9Ttv8AN3letX4ekmxb1cjJVwbwf 6v5UN/B6dL/BlQ0lK504dAlUoicADPeBj+w5JtLSKTroC3ds8m5UeYRMfC8Wype03pqa 6H0Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=eG+W77W+J+qtF46C5MDSRNfDqjTtT0wFs7JPjVurgBs=; b=Xwhu69D7RmOhgwKHAGoX/dhu8Vt3hTW46h9VxGgzqaoaT82D4Jb28UtKI6qWA+jliM 6dJKkvPzucfhub+77BFsrE93xgWzEQ578OuiDDrf4X9am6XJuhdp623ojZq3GvmEuALE MZ6lq4X7JCR/Tsf4J5EhrTk+2ScP43V9ioJtS39ew9n4wFR97/yZosMujgi7zaGrbSpw NCwBjTsxeUg540ux+wxSQTItPYxBzZseaUJuuK+I07Oq93md3ZnB4X3LIOl9JSypFbT0 xzy4xqC6JQ2PLvPeq55fCG/9cS+mRUr6ZCkIyYCothRY2f1DnV5/BHOywbaGXOu0ddkH vbIQ== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , Alexander Aring , Stefan Schmidt , syzbot , "David S. Miller" Subject: [PATCH 4.9 07/28] ieee802154: 6lowpan: fix possible NULL deref in lowpan_device_event() Date: Thu, 29 Mar 2018 20:00:26 +0200 Message-Id: <20180329175734.385283539@linuxfoundation.org> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180329175733.447823703@linuxfoundation.org> References: <20180329175733.447823703@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1596296051714340324?= X-GMAIL-MSGID: =?utf-8?q?1596296362415281450?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit ca0edb131bdf1e6beaeb2b8289fd6b374b74147d ] A tun device type can trivially be set to arbitrary value using TUNSETLINK ioctl(). Therefore, lowpan_device_event() must really check that ieee802154_ptr is not NULL. Fixes: 2c88b5283f60d ("ieee802154: 6lowpan: remove check on null") Signed-off-by: Eric Dumazet Cc: Alexander Aring Cc: Stefan Schmidt Reported-by: syzbot Acked-by: Stefan Schmidt Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ieee802154/6lowpan/core.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/net/ieee802154/6lowpan/core.c +++ b/net/ieee802154/6lowpan/core.c @@ -204,9 +204,13 @@ static inline void lowpan_netlink_fini(v static int lowpan_device_event(struct notifier_block *unused, unsigned long event, void *ptr) { - struct net_device *wdev = netdev_notifier_info_to_dev(ptr); + struct net_device *ndev = netdev_notifier_info_to_dev(ptr); + struct wpan_dev *wpan_dev; - if (wdev->type != ARPHRD_IEEE802154) + if (ndev->type != ARPHRD_IEEE802154) + return NOTIFY_DONE; + wpan_dev = ndev->ieee802154_ptr; + if (!wpan_dev) return NOTIFY_DONE; switch (event) { @@ -215,8 +219,8 @@ static int lowpan_device_event(struct no * also delete possible lowpan interfaces which belongs * to the wpan interface. */ - if (wdev->ieee802154_ptr->lowpan_dev) - lowpan_dellink(wdev->ieee802154_ptr->lowpan_dev, NULL); + if (wpan_dev->lowpan_dev) + lowpan_dellink(wpan_dev->lowpan_dev, NULL); break; default: return NOTIFY_DONE;