From: Stephen Suryaputra <ssuryaextr@gmail.com>
Date: Fri, 1 Jun 2018 00:05:21 -0400
Subject: vrf: check the original netdevice for generating redirect
Git-commit: 2f17becfbea5e9a0529b51da7345783e96e69516
Patch-mainline: v4.18-rc1
References: networking-stable-18_06_08

Use the right device to determine if redirect should be sent especially
when using vrf. Same as well as when sending the redirect.

Signed-off-by: Stephen Suryaputra <ssuryaextr@gmail.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 net/ipv6/ip6_output.c |    3 ++-
 net/ipv6/ndisc.c      |    6 ++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -498,7 +498,8 @@ int ip6_forward(struct sk_buff *skb)
 	   send redirects to source routed frames.
 	   We don't send redirects to frames decapsulated from IPsec.
 	 */
-	if (skb->dev == dst->dev && opt->srcrt == 0 && !skb_sec_path(skb)) {
+	if (IP6CB(skb)->iif == dst->dev->ifindex &&
+	    opt->srcrt == 0 && !skb_sec_path(skb)) {
 		struct in6_addr *target = NULL;
 		struct inet_peer *peer;
 		struct rt6_info *rt;
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1568,6 +1568,12 @@ void ndisc_send_redirect(struct sk_buff
 	   ops_data_buf[NDISC_OPS_REDIRECT_DATA_SPACE], *ops_data = NULL;
 	bool ret;
 
+	if (netif_is_l3_master(skb->dev)) {
+		dev = __dev_get_by_index(dev_net(skb->dev), IPCB(skb)->iif);
+		if (!dev)
+			return;
+	}
+
 	if (ipv6_get_lladdr(dev, &saddr_buf, IFA_F_TENTATIVE)) {
 		ND_PRINTK(2, warn, "Redirect: no link-local address on %s\n",
 			  dev->name);