From 1c9b7aa1eb40ab708ef3242f74b9a61487623168 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Wed, 9 Jan 2008 03:51:59 -0800 Subject: [PATCH] [ATM]: Check IP header validity in mpc_send_packet Al went through the ip_fast_csum callers and found this piece of code that did not validate the IP header. While root crashing the machine by sending bogus packets through raw or AF_PACKET sockets isn't that serious, it is still nice to react gracefully. This patch ensures that the skb has enough data for an IP header and that the header length field is valid. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- net/atm/mpc.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/atm/mpc.c b/net/atm/mpc.c index 2086396de1..9c7f712fc7 100644 --- a/net/atm/mpc.c +++ b/net/atm/mpc.c @@ -542,6 +542,13 @@ static int mpc_send_packet(struct sk_buff *skb, struct net_device *dev) if (eth->h_proto != htons(ETH_P_IP)) goto non_ip; /* Multi-Protocol Over ATM :-) */ + /* Weed out funny packets (e.g., AF_PACKET or raw). */ + if (skb->len < ETH_HLEN + sizeof(struct iphdr)) + goto non_ip; + skb_set_network_header(skb, ETH_HLEN); + if (skb->len < ETH_HLEN + ip_hdr(skb)->ihl * 4 || ip_hdr(skb)->ihl < 5) + goto non_ip; + while (i < mpc->number_of_mps_macs) { if (!compare_ether_addr(eth->h_dest, (mpc->mps_macs + i*ETH_ALEN))) if ( send_via_shortcut(skb, mpc) == 0 ) /* try shortcut */ -- 2.39.5