[PATCH 5.4 69/84] ip6_gre: Avoid updating tunnel->tun_hlen in __gre6_xmit()

Greg Kroah-Hartman
2022-05-04T16:52:09Z

From: Peilin Ye <peilin.ye@bytedance.com>

[ Upstream commit f40c064e933d7787ca7411b699504d7a2664c1f5 ]

Do not update tunnel->tun_hlen in data plane code. Use a local variable
instead, just like "tunnel_hlen" in net/ipv4/ip_gre.c:gre_fb_xmit().

Co-developed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv6/ip6_gre.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index 5dbc280d4385..e550db28aabb 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -730,6 +730,7 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
struct ip_tunnel_info *tun_info;
const struct ip_tunnel_key *key;
__be16 flags;
+ int tun_hlen;

tun_info = skb_tunnel_info(skb);
if (unlikely(!tun_info ||
@@ -748,9 +749,9 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb,
dsfield = key->tos;
flags = key->tun_flags &
(TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
- tunnel->tun_hlen = gre_calc_hlen(flags);
+ tun_hlen = gre_calc_hlen(flags);

- gre_build_header(skb, tunnel->tun_hlen,
+ gre_build_header(skb, tun_hlen,
flags, protocol,
tunnel_id_to_key32(tun_info->key.tun_id),
(flags & TUNNEL_SEQ) ? htonl(tunnel->o_seqno++)
--
2.35.1