[PATCH 3.12 102/113] net: 6lowpan: fix lowpan_header_create non-compression memcpy call

[Jiri Slaby]

From: Daniel Borkmann <dborkman@xxxxxxxxxx>

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

===============

commit 965801e1eb624154fe5e9dc5d2ff0b7f1951a11c upstream.

In function lowpan_header_create(), we invoke the following code
construct:

  struct ipv6hdr *hdr;
  ...
  hdr = ipv6_hdr(skb);
  ...
  if (...)
    memcpy(hc06_ptr + 1, &hdr->flow_lbl[1], 2);
  else
    memcpy(hc06_ptr, &hdr, 4);

Where the else path of the condition, that is, non-compression
path, calls memcpy() with a pointer to struct ipv6hdr *hdr as
source, thus two levels of indirection. This cannot be correct,
and likely only one level of pointer was intended as source
buffer for memcpy() here.

Fixes: 44331fe2aa0d ("IEEE802.15.4: 6LoWPAN basic support")
Signed-off-by: Daniel Borkmann <dborkman@xxxxxxxxxx>
Cc: Alexander Smirnov <alex.bluesman.smirnov@xxxxxxxxx>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
Cc: Werner Almesberger <werner@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
 net/ieee802154/6lowpan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 70348be444c1..a377d435756e 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -548,7 +548,7 @@ static int lowpan_header_create(struct sk_buff *skb,
 			hc06_ptr += 3;
 		} else {
 			/* compress nothing */
-			memcpy(hc06_ptr, &hdr, 4);
+			memcpy(hc06_ptr, hdr, 4);
 			/* replace the top byte with new ECN | DSCP format */
 			*hc06_ptr = tmp;
 			hc06_ptr += 4;
-- 
2.12.0