[PATCH 4.20 008/145] ieee802154: lowpan_header_create check must check daddr

[Greg Kroah-Hartman]

4.20-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Willem de Bruijn <willemb@xxxxxxxxxx>

[ Upstream commit 40c3ff6d5e0809505a067dd423c110c5658c478c ]

Packet sockets may call dev_header_parse with NULL daddr. Make
lowpan_header_ops.create fail.

Fixes: 87a93e4eceb4 ("ieee802154: change needed headroom/tailroom")
Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Acked-by: Alexander Aring <aring@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 net/ieee802154/6lowpan/tx.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/net/ieee802154/6lowpan/tx.c
+++ b/net/ieee802154/6lowpan/tx.c
@@ -48,6 +48,9 @@ int lowpan_header_create(struct sk_buff
 	const struct ipv6hdr *hdr = ipv6_hdr(skb);
 	struct neighbour *n;
 
+	if (!daddr)
+		return -EINVAL;
+
 	/* TODO:
 	 * if this package isn't ipv6 one, where should it be routed?
 	 */