From 8cfad496c4257441710735ccef622f3829870164 Mon Sep 17 00:00:00 2001 From: Phoebe Buckheister Date: Mon, 17 Mar 2014 18:30:19 +0100 Subject: ieee802154: properly unshare skbs in ieee802154 *_rcv functions ieee802154 sockets do not properly unshare received skbs, which leads to panics (at least) when they are used in conjunction with 6lowpan, so run skb_share_check on received skbs. 6lowpan also contains a use-after-free, which is trivially fixed by replacing the inlined skb_share_check with the explicit call. Signed-off-by: Phoebe Buckheister Tested-by: Alexander Aring Signed-off-by: David S. Miller --- net/ieee802154/6lowpan_rtnl.c | 29 +++++++++++++---------------- net/ieee802154/dgram.c | 4 ++++ net/ieee802154/raw.c | 4 ++++ 3 files changed, 21 insertions(+), 16 deletions(-) (limited to 'net/ieee802154') diff --git a/net/ieee802154/6lowpan_rtnl.c b/net/ieee802154/6lowpan_rtnl.c index 606039442a59..0f5a69ed746d 100644 --- a/net/ieee802154/6lowpan_rtnl.c +++ b/net/ieee802154/6lowpan_rtnl.c @@ -447,10 +447,13 @@ static int lowpan_validate(struct nlattr *tb[], struct nlattr *data[]) static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { - struct sk_buff *local_skb; struct ieee802154_hdr hdr; int ret; + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + goto drop; + if (!netif_running(dev)) goto drop_skb; @@ -460,42 +463,36 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev, if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0) goto drop_skb; - local_skb = skb_clone(skb, GFP_ATOMIC); - if (!local_skb) - goto drop_skb; - - kfree_skb(skb); - /* check that it's our buffer */ if (skb->data[0] == LOWPAN_DISPATCH_IPV6) { - local_skb->protocol = htons(ETH_P_IPV6); - local_skb->pkt_type = PACKET_HOST; + skb->protocol = htons(ETH_P_IPV6); + skb->pkt_type = PACKET_HOST; /* Pull off the 1-byte of 6lowpan header. */ - skb_pull(local_skb, 1); + skb_pull(skb, 1); - ret = lowpan_give_skb_to_devices(local_skb, NULL); + ret = lowpan_give_skb_to_devices(skb, NULL); if (ret == NET_RX_DROP) goto drop; } else { switch (skb->data[0] & 0xe0) { case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */ - ret = process_data(local_skb, &hdr); + ret = process_data(skb, &hdr); if (ret == NET_RX_DROP) goto drop; break; case LOWPAN_DISPATCH_FRAG1: /* first fragment header */ - ret = lowpan_frag_rcv(local_skb, LOWPAN_DISPATCH_FRAG1); + ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAG1); if (ret == 1) { - ret = process_data(local_skb, &hdr); + ret = process_data(skb, &hdr); if (ret == NET_RX_DROP) goto drop; } break; case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */ - ret = lowpan_frag_rcv(local_skb, LOWPAN_DISPATCH_FRAGN); + ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAGN); if (ret == 1) { - ret = process_data(local_skb, &hdr); + ret = process_data(skb, &hdr); if (ret == NET_RX_DROP) goto drop; } diff --git a/net/ieee802154/dgram.c b/net/ieee802154/dgram.c index 4c47154041b0..6d251a35bdc4 100644 --- a/net/ieee802154/dgram.c +++ b/net/ieee802154/dgram.c @@ -329,6 +329,10 @@ out: static int dgram_rcv_skb(struct sock *sk, struct sk_buff *skb) { + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + return NET_RX_DROP; + if (sock_queue_rcv_skb(sk, skb) < 0) { kfree_skb(skb); return NET_RX_DROP; diff --git a/net/ieee802154/raw.c b/net/ieee802154/raw.c index e5258cf6773b..74d54fae33d7 100644 --- a/net/ieee802154/raw.c +++ b/net/ieee802154/raw.c @@ -213,6 +213,10 @@ out: static int raw_rcv_skb(struct sock *sk, struct sk_buff *skb) { + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + return NET_RX_DROP; + if (sock_queue_rcv_skb(sk, skb) < 0) { kfree_skb(skb); return NET_RX_DROP; -- cgit v1.2.3