| From 55441070ca1cbd47ce1ad2959bbf4b47aed9b83b Mon Sep 17 00:00:00 2001 |
| From: Glenn Ruben Bakke <glennrubenbakke@nordicsemi.no> |
| Date: Fri, 22 Apr 2016 18:06:11 +0200 |
| Subject: Bluetooth: 6lowpan: Fix memory corruption of ipv6 destination address |
| |
| From: Glenn Ruben Bakke <glennrubenbakke@nordicsemi.no> |
| |
| 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> |
| |
| |
| --- |
| net/bluetooth/6lowpan.c | 11 ++++------- |
| 1 file changed, 4 insertions(+), 7 deletions(-) |
| |
| --- a/net/bluetooth/6lowpan.c |
| +++ b/net/bluetooth/6lowpan.c |
| @@ -431,15 +431,18 @@ static int setup_header(struct sk_buff * |
| 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 |
| 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; |
| } |
| |
