Patch "ieee802154: 6lowpan: fix possible NULL deref in lowpan_device_event()" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

ieee802154: 6lowpan: fix possible NULL deref in lowpan_device_event()

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
ieee802154-6lowpan-fix-possible-null-deref-in-lowpan_device_event.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Eric Dumazet <[email protected]>
Date: Mon, 5 Mar 2018 08:51:03 -0800
Subject: ieee802154: 6lowpan: fix possible NULL deref in lowpan_device_event()

From: Eric Dumazet <[email protected]>

[ 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.

---
 net/ieee802154/6lowpan/core.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

@@ -206,9 +206,13 @@ 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) {

@@ -217,8 +221,8 @@ 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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/ipv6-fix-access-to-non-linear-packet-in-ndisc_fill_redirect_hdr_option.patch queue-4.15/skbuff-fix-not-waking-applications-when-errors-are-enqueued.patch queue-4.15/l2tp-do-not-accept-arbitrary-sockets.patch queue-4.15/tcp-purge-write-queue-upon-aborting-the-connection.patch queue-4.15/net-use-skb_to_full_sk-in-skb_update_prio.patch queue-4.15/ieee802154-6lowpan-fix-possible-null-deref-in-lowpan_device_event.patch