From 4666248379e95f659710e2f5ea69883cf799b40b Mon Sep 17 00:00:00 2001
From: Willem de Bruijn <willemb@google.com>
Date: Mon, 6 Sep 2021 10:27:38 -0400
Subject: [PATCH] ip6_gre: Revert "ip6_gre: add validation for csum_start"
Git-commit: fe63339ef36bfb1cc12962015a9b254170eea057
Patch-mainline: v5.15-rc1
References: stable-5.14.7
[ Upstream commit fe63339ef36bfb1cc12962015a9b254170eea057 ]
This reverts commit 9cf448c200ba9935baa94e7a0964598ce947db9d.
This commit was added for equivalence with a similar fix to ip_gre.
That fix proved to have a bug. Upon closer inspection, ip6_gre is not
susceptible to the original bug.
So revert the unnecessary extra check.
In short, ipgre_xmit calls skb_pull to remove ipv4 headers previously
inserted by dev_hard_header. ip6gre_tunnel_xmit does not.
Link: https://lore.kernel.org/netdev/CA+FuTSe+vJgTVLc9SojGuN-f9YQ+xWLPKE_S4f=f+w+_P2hgUg@mail.gmail.com/#t
Fixes: 9cf448c200ba ("ip6_gre: add validation for csum_start")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
net/ipv6/ip6_gre.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 7a5e90e09363..bc224f917bbd 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -629,8 +629,6 @@ static int gre_rcv(struct sk_buff *skb)
static int gre_handle_offloads(struct sk_buff *skb, bool csum)
{
- if (csum && skb_checksum_start(skb) < skb->data)
- return -EINVAL;
return iptunnel_handle_offloads(skb,
csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
}
--
2.26.2