diff options
| author | Glenn Ruben Bakke <glennrubenbakke@nordicsemi.no> | 2016-04-22 18:06:11 +0200 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2016-04-26 01:08:25 +0200 |
| commit | 55441070ca1cbd47ce1ad2959bbf4b47aed9b83b (patch) | |
| tree | 520b1520d798b485a4fafcda388331ac23c65027 | |
| parent | 5c0e03cd9f10d541b69b667a2b1b8980f196f432 (diff) | |
Bluetooth: 6lowpan: Fix memory corruption of ipv6 destination address
The memcpy of ipv6 header destination address to the skb control block
(sbk->cb) in header_create() results in currupted memory when bt_xmit()
is issued. The skb->cb is "released" in the return of header_create()
making room for lower layer to minipulate the skb->cb.
The value retrieved in bt_xmit is not persistent across header creation
and sending, and the lower layer will overwrite portions of skb->cb,
making the copied destination address wrong.
The memory corruption will lead to non-working multicast as the first 4
bytes of the copied destination address is replaced by a value that
resolves into a non-multicast prefix.
This fix removes the dependency on the skb control block between header
creation and send, by moving the destination address memcpy to the send
function path (setup_create, which is called from bt_xmit).
Signed-off-by: Glenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 4.5+
| -rw-r--r-- | net/bluetooth/6lowpan.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c index 38e82ddd7ccd..780089d75915 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -434,15 +434,18 @@ static int setup_header(struct sk_buff *skb, struct net_device *netdev, bdaddr_t *peer_addr, u8 *peer_addr_type) { struct in6_addr ipv6_daddr; + struct ipv6hdr *hdr; struct lowpan_btle_dev *dev; struct lowpan_peer *peer; bdaddr_t addr, *any = BDADDR_ANY; u8 *daddr = any->b; int err, status = 0; + hdr = ipv6_hdr(skb); + dev = lowpan_btle_dev(netdev); - memcpy(&ipv6_daddr, &lowpan_cb(skb)->addr, sizeof(ipv6_daddr)); + memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr)); if (ipv6_addr_is_multicast(&ipv6_daddr)) { lowpan_cb(skb)->chan = NULL; @@ -492,15 +495,9 @@ static int header_create(struct sk_buff *skb, struct net_device *netdev, unsigned short type, const void *_daddr, const void *_saddr, unsigned int len) { - struct ipv6hdr *hdr; - if (type != ETH_P_IPV6) return -EINVAL; - hdr = ipv6_hdr(skb); - - memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, sizeof(struct in6_addr)); - return 0; } |