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From:   Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
To:     Pablo Neira Ayuso <pablo@netfilter.org>,
        Jozsef Kadlecsik <kadlec@netfilter.org>,
        Florian Westphal <fw@strlen.de>
Cc:     netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Subject: [PATCH v2 1/2] netfilter: nf_flow_table: reload ip{v6}h in nf_flow_nat_ip{v6}
Date:   Tue, 17 Mar 2020 10:02:52 +0800
Message-Id: <1584410573-6812-1-git-send-email-yanhaishuang@cmss.chinamobile.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Since nf_flow_snat_port and nf_flow_snat_ip{v6} call pskb_may_pull()
which may change skb->data, so we need to reload ip{v6}h at the right
palce.

Fixes: a908fdec3dda ("netfilter: nf_flow_table: move ipv6 offload hook
code to nf_flow_table")
Fixes: 7d2086871762 ("netfilter: nf_flow_table: move ipv4 offload hook
code to nf_flow_table")
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
---
v2: collapse the patches
---
 net/netfilter/nf_flow_table_ip.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c
index 5272721..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;
@@ -417,11 +418,12 @@ static int nf_flow_nat_ipv6(const struct flow_offload *flow,
 
 	if (test_bit(NF_FLOW_SNAT, &flow->flags) &&
 	    (nf_flow_snat_port(flow, skb, thoff, ip6h->nexthdr, dir) < 0 ||
-	     nf_flow_snat_ipv6(flow, skb, ip6h, thoff, dir) < 0))
+	     nf_flow_snat_ipv6(flow, skb, ipv6_hdr(skb), thoff, dir) < 0))
 		return -1;
+	ip6h = ipv6_hdr(skb);
 	if (test_bit(NF_FLOW_DNAT, &flow->flags) &&
 	    (nf_flow_dnat_port(flow, skb, thoff, ip6h->nexthdr, dir) < 0 ||
-	     nf_flow_dnat_ipv6(flow, skb, ip6h, thoff, dir) < 0))
+	     nf_flow_dnat_ipv6(flow, skb, ipv6_hdr(skb), thoff, dir) < 0))
 		return -1;
 
 	return 0;
-- 
1.8.3.1