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| author | Glenn Ruben Bakke <glennrubenbakke@nordicsemi.no> | 2016-04-22 18:06:11 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-06-07 18:23:40 -0700 |
| commit | 35cde4017ac929e8d2dae57de54f84e476e24bb3 (patch) | |
| tree | e2dde2f98e31f05ee9adb1ac86ebcb91fdd615ac | |
| parent | 5d82a4b5bc708ab30cf41cb024f8d45b31987374 (diff) | |
| download | lwn-35cde4017ac929e8d2dae57de54f84e476e24bb3.tar.gz lwn-35cde4017ac929e8d2dae57de54f84e476e24bb3.zip | |
Bluetooth: 6lowpan: Fix memory corruption of ipv6 destination address
commit 55441070ca1cbd47ce1ad2959bbf4b47aed9b83b upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 8a4cc2f7f0db..e45cb9155039 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -431,15 +431,18 @@ 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_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_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; @@ -489,15 +492,9 @@ 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; } |