Commit 70c261d5 authored by Pablo Neira Ayuso's avatar Pablo Neira Ayuso
Browse files

netfilter: nf_tables_ipv6: consider network offset in netdev/egress validation 



From netdev/egress, skb->len can include the ethernet header, therefore,
subtract network offset from skb->len when validating IPv6 packet length.

Fixes: 42df6e1d ("netfilter: Introduce egress hook")
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 5fd06289

include/net/netfilter/nf_tables_ipv6.h

+3 −2
Original line number Diff line number Diff line
@@ -31,8 +31,8 @@ static inline int __nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt) 
	struct ipv6hdr *ip6h, _ip6h;

	unsigned int thoff = 0;

	unsigned short frag_off;

	u32 pkt_len, skb_len;

	int protohdr;

	u32 pkt_len;



	ip6h = skb_header_pointer(pkt->skb, skb_network_offset(pkt->skb),

				  sizeof(*ip6h), &_ip6h);
@@ -43,7 +43,8 @@ static inline int __nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt) 
		return -1;



	pkt_len = ntohs(ip6h->payload_len);

	if (pkt_len + sizeof(*ip6h) > pkt->skb->len)

	skb_len = pkt->skb->len - skb_network_offset(pkt->skb);

	if (pkt_len + sizeof(*ip6h) > skb_len)

		return -1;



	protohdr = ipv6_find_hdr(pkt->skb, &thoff, -1, &frag_off, &flags);