From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Wed, 20 Apr 2005 05:48:59 +0000 (-0700)
Subject: [IPSEC]: COW skb header in UDP decap
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=4d78b6c78ae6d87e4c1c8072f42efa716f04afb9;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

[IPSEC]: COW skb header in UDP decap

The following patch just makes the header part of the skb writeable.
This is needed since we modify the IP headers just a few lines below.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 6baddfbedca3..8a213238f287 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -955,6 +955,8 @@ static int udp_encap_rcv(struct sock * sk, struct sk_buff *skb)
 	 * header and optional ESP marker bytes) and then modify the
 	 * protocol to ESP, and then call into the transform receiver.
 	 */
+	if (skb_cloned(skb) && pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+		return 0;
 
 	/* Now we can update and verify the packet length... */
 	iph = skb->nh.iph;