From 1eeceae48fdc6e6fcb71403010ef5dd863b7ef2f Mon Sep 17 00:00:00 2001 From: Hannes Frederic Sowa Date: Fri, 16 Aug 2013 13:30:07 +0200 Subject: ipv6: drop packets with multiple fragmentation headers [ Upstream commit f46078cfcd77fa5165bf849f5e568a7ac5fa569c ] It is not allowed for an ipv6 packet to contain multiple fragmentation headers. So discard packets which were already reassembled by fragmentation logic and send back a parameter problem icmp. The updates for RFC 6980 will come in later, I have to do a bit more research here. Cc: YOSHIFUJI Hideaki Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/linux/ipv6.h | 1 + net/ipv6/reassembly.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 0c99776..84b1447 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -255,6 +255,7 @@ struct inet6_skb_parm { #define IP6SKB_XFRM_TRANSFORMED 1 #define IP6SKB_FORWARDED 2 #define IP6SKB_REROUTED 4 +#define IP6SKB_FRAGMENTED 16 }; #define IP6CB(skb) ((struct inet6_skb_parm*)((skb)->cb)) diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c index 0b525c2..cc332c0 100644 --- a/net/ipv6/reassembly.c +++ b/net/ipv6/reassembly.c @@ -516,6 +516,7 @@ static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev, head->tstamp = fq->q.stamp; ipv6_hdr(head)->payload_len = htons(payload_len); IP6CB(head)->nhoff = nhoff; + IP6CB(head)->flags |= IP6SKB_FRAGMENTED; /* Yes, and fold redundant checksum back. 8) */ if (head->ip_summed == CHECKSUM_COMPLETE) @@ -551,6 +552,9 @@ static int ipv6_frag_rcv(struct sk_buff *skb) const struct ipv6hdr *hdr = ipv6_hdr(skb); struct net *net = dev_net(skb_dst(skb)->dev); + if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED) + goto fail_hdr; + IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS); /* Jumbo payload inhibits frag. header */ @@ -571,6 +575,7 @@ static int ipv6_frag_rcv(struct sk_buff *skb) ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS); IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb); + IP6CB(skb)->flags |= IP6SKB_FRAGMENTED; return 1; } -- cgit v1.1