[PATCH 4.19 29/86] ping: fix the sk_bound_dev_if match in ping_lookup

Greg Kroah-Hartman
2022-02-07T11:19:59Z

From: Xin Long <lucien.xin@gmail.com>

commit 2afc3b5a31f9edf3ef0f374f5d70610c79c93a42 upstream.

When 'ping' changes to use PING socket instead of RAW socket by:

# sysctl -w net.ipv4.ping_group_range="0 100"

the selftests 'router_broadcast.sh' will fail, as such command

# ip vrf exec vrf-h1 ping -I veth0 198.51.100.255 -b

can't receive the response skb by the PING socket. It's caused by mismatch
of sk_bound_dev_if and dif in ping_rcv() when looking up the PING socket,
as dif is vrf-h1 if dif's master was set to vrf-h1.

This patch is to fix this regression by also checking the sk_bound_dev_if
against sdif so that the packets can stil be received even if the socket
is not bound to the vrf device but to the real iif.

Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind")
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/ping.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -225,7 +225,8 @@ static struct sock *ping_lookup(struct n
continue;
}

- if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)
+ if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
+ sk->sk_bound_dev_if != inet_sdif(skb))
continue;

sock_hold(sk);