diff options
| author | Eric Dumazet <edumazet@google.com> | 2013-02-08 18:48:21 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-02-10 20:39:39 -0500 |
| commit | 044453b3efdc90bdd5feffe74b99d95dec70ac43 (patch) | |
| tree | 62f3107f82879cc5aeec7cf02f39f7e37de07a41 /net/ipv4/arp.c | |
| parent | 839c8cc32bc252345f4d5767d2d6cf695f2124ab (diff) | |
arp: fix possible crash in arp_rcv()
We should call skb_share_check() before pskb_may_pull(), or we
can crash in pskb_expand_head()
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/arp.c')
| -rw-r--r-- | net/ipv4/arp.c | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index 9547a273b9e9..ded146b217f1 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -928,24 +928,25 @@ static void parp_redo(struct sk_buff *skb) static int arp_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { - struct arphdr *arp; + const struct arphdr *arp; + + if (dev->flags & IFF_NOARP || + skb->pkt_type == PACKET_OTHERHOST || + skb->pkt_type == PACKET_LOOPBACK) + goto freeskb; + + skb = skb_share_check(skb, GFP_ATOMIC); + if (!skb) + goto out_of_mem; /* ARP header, plus 2 device addresses, plus 2 IP addresses. */ if (!pskb_may_pull(skb, arp_hdr_len(dev))) goto freeskb; arp = arp_hdr(skb); - if (arp->ar_hln != dev->addr_len || - dev->flags & IFF_NOARP || - skb->pkt_type == PACKET_OTHERHOST || - skb->pkt_type == PACKET_LOOPBACK || - arp->ar_pln != 4) + if (arp->ar_hln != dev->addr_len || arp->ar_pln != 4) goto freeskb; - skb = skb_share_check(skb, GFP_ATOMIC); - if (skb == NULL) - goto out_of_mem; - memset(NEIGH_CB(skb), 0, sizeof(struct neighbour_cb)); return NF_HOOK(NFPROTO_ARP, NF_ARP_IN, skb, dev, NULL, arp_process); |