[ Upstream commit 33cc3c0cfa64c86b6c4bbee86997aea638534931 ] nf_flow_offload_ip_hook() and nf_flow_offload_ipv6_hook() do not check ttl value. So, ttl value overflow may occur. Fixes: 97add9f0d66d ("netfilter: flow table support for IPv4") Fixes: 0995210753a2 ("netfilter: flow table support for IPv6") Signed-off-by: Taehee Yoo <ap420073@xxxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/netfilter/nf_flow_table_ip.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index 1d291a51cd45..46022a2867d7 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -181,6 +181,9 @@ static int nf_flow_tuple_ip(struct sk_buff *skb, const struct net_device *dev, iph->protocol != IPPROTO_UDP) return -1; + if (iph->ttl <= 1) + return -1; + thoff = iph->ihl * 4; if (!pskb_may_pull(skb, thoff + sizeof(*ports))) return -1; @@ -411,6 +414,9 @@ static int nf_flow_tuple_ipv6(struct sk_buff *skb, const struct net_device *dev, ip6h->nexthdr != IPPROTO_UDP) return -1; + if (ip6h->hop_limit <= 1) + return -1; + thoff = sizeof(*ip6h); if (!pskb_may_pull(skb, thoff + sizeof(*ports))) return -1; -- 2.20.1