[PATCH 4.20 54/76] ipv4: Pass original device to ip_rcv_finish_core

Greg Kroah-Hartman
2019-03-08T12:56:01Z

From: David Ahern <dsahern@gmail.com>

[ Upstream commit a1fd1ad2552fad9e649eeb85fd79301e2880a886 ]

ip_route_input_rcu expects the original ingress device (e.g., for
proper multicast handling). The skb->dev can be changed by l3mdev_ip_rcv,
so dev needs to be saved prior to calling it. This was the behavior prior
to the listify changes.

Fixes: 5fa12739a53d0 ("net: ipv4: listify ip_rcv_finish")
Cc: Edward Cree <ecree@solarflare.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv4/ip_input.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c
@@ -308,11 +308,10 @@ drop:
}

static int ip_rcv_finish_core(struct net *net, struct sock *sk,
- struct sk_buff *skb)
+ struct sk_buff *skb, struct net_device *dev)
{
const struct iphdr *iph = ip_hdr(skb);
int (*edemux)(struct sk_buff *skb);
- struct net_device *dev = skb->dev;
struct rtable *rt;
int err;

@@ -401,6 +400,7 @@ drop_error:

static int ip_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
+ struct net_device *dev = skb->dev;
int ret;

/* if ingress device is enslaved to an L3 master device pass the
@@ -410,7 +410,7 @@ static int ip_rcv_finish(struct net *net
if (!skb)
return NET_RX_SUCCESS;

- ret = ip_rcv_finish_core(net, sk, skb);
+ ret = ip_rcv_finish_core(net, sk, skb, dev);
if (ret != NET_RX_DROP)
ret = dst_input(skb);
return ret;
@@ -546,6 +546,7 @@ static void ip_list_rcv_finish(struct ne

INIT_LIST_HEAD(&sublist);
list_for_each_entry_safe(skb, next, head, list) {
+ struct net_device *dev = skb->dev;
struct dst_entry *dst;

skb_list_del_init(skb);
@@ -555,7 +556,7 @@ static void ip_list_rcv_finish(struct ne
skb = l3mdev_ip_rcv(skb);
if (!skb)
continue;
- if (ip_rcv_finish_core(net, sk, skb) == NET_RX_DROP)
+ if (ip_rcv_finish_core(net, sk, skb, dev) == NET_RX_DROP)
continue;

dst = skb_dst(skb);