Since nf_flow_snat_port and nf_flow_snat_ip call pskb_may_pull() which may change skb->data, so we need to reload iph at the right place. Fixes: 7d2086871762 ("netfilter: nf_flow_table: move ipv4 offload hook code to nf_flow_table") Signed-off-by: Haishuang Yan <yanhaishuang@xxxxxxxxxxxxxxxxxxxx> --- net/netfilter/nf_flow_table_ip.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index 2e6ebbe..942bda5 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -146,11 +146,12 @@ static int nf_flow_nat_ip(const struct flow_offload *flow, struct sk_buff *skb, if (test_bit(NF_FLOW_SNAT, &flow->flags) && (nf_flow_snat_port(flow, skb, thoff, iph->protocol, dir) < 0 || - nf_flow_snat_ip(flow, skb, iph, thoff, dir) < 0)) + nf_flow_snat_ip(flow, skb, ip_hdr(skb), thoff, dir) < 0)) return -1; + iph = ip_hdr(skb); if (test_bit(NF_FLOW_DNAT, &flow->flags) && (nf_flow_dnat_port(flow, skb, thoff, iph->protocol, dir) < 0 || - nf_flow_dnat_ip(flow, skb, iph, thoff, dir) < 0)) + nf_flow_dnat_ip(flow, skb, ip_hdr(skb), thoff, dir) < 0)) return -1; return 0; -- 1.8.3.1