Hi,
Please cherry-pick 0e78a87 to 4.11.y. It fixes IPSec through NAT regression in 4.11.
Thanks,
Ortwin
From 0e78a87306a6f55b1c7bbafad1de62c3975953ca Mon Sep 17 00:00:00 2001
From: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Date: Wed, 3 May 2017 08:44:27 +0200
Subject: esp4: Fix udpencap for local TCP packets.
Locally generated TCP packets are usually cloned, so we
do skb_cow_data() on this packets. After that we need to
reload the pointer to the esp header. On udpencap this
header has an offset to skb_transport_header, so take this
offset into account.
Fixes: 67d349ed603 ("net/esp4: Fix invalid esph pointer crash")
Fixes: fca11ebde3f0 ("esp4: Reorganize esp_output")
Reported-by: Don Bowman <db@xxxxxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c
index 65cc02bd82bc..93322f895eab 100644
--- a/net/ipv4/esp4.c
+++ b/net/ipv4/esp4.c
@@ -248,6 +248,7 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *
u8 *tail;
u8 *vaddr;
int nfrags;
+ int esph_offset;
struct page *page;
struct sk_buff *trailer;
int tailen = esp->tailen;
@@ -313,11 +314,13 @@ int esp_output_head(struct xfrm_state *x, struct sk_buff *skb, struct esp_info *
}
cow:
+ esph_offset = (unsigned char *)esp->esph - skb_transport_header(skb);
+
nfrags = skb_cow_data(skb, tailen, &trailer);
if (nfrags < 0)
goto out;
tail = skb_tail_pointer(trailer);
- esp->esph = ip_esp_hdr(skb);
+ esp->esph = (struct ip_esp_hdr *)(skb_transport_header(skb) + esph_offset);
skip_cow:
esp_output_fill_trailer(tail, esp->tfclen, esp->plen, esp->proto);