When replying to a ICMPv6 echo request that comes from localhost address the right output ifindex is 1 (lo) and not rt6i_idev dev index. Use the skb device ifindex instead. This fixes pinging to a local address from localhost source address.
$ ping6 -I ::1 2001:1:1::2 -c 3 PING 2001:1:1::2 (2001:1:1::2) from ::1 : 56 data bytes 64 bytes from 2001:1:1::2: icmp_seq=1 ttl=64 time=0.037 ms 64 bytes from 2001:1:1::2: icmp_seq=2 ttl=64 time=0.069 ms 64 bytes from 2001:1:1::2: icmp_seq=3 ttl=64 time=0.122 ms
2001:1:1::2 ping statistics 3 packets transmitted, 3 received, 0% packet loss, time 2032ms rtt min/avg/max/mdev = 0.037/0.076/0.122/0.035 ms
Fixes: 1b70d792cf67 ("ipv6: Use rt6i_idev index for echo replies to a local address") Signed-off-by: Fernando Fernandez Mancera fmancera@suse.de --- v2: no changes --- net/ipv6/icmp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 5d2f90babaa5..5de254043133 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -965,7 +965,9 @@ static enum skb_drop_reason icmpv6_echo_reply(struct sk_buff *skb) fl6.daddr = ipv6_hdr(skb)->saddr; if (saddr) fl6.saddr = *saddr; - fl6.flowi6_oif = icmp6_iif(skb); + fl6.flowi6_oif = ipv6_addr_type(&fl6.daddr) & IPV6_ADDR_LOOPBACK ? + skb->dev->ifindex : + icmp6_iif(skb); fl6.fl6_icmp_type = type; fl6.flowi6_mark = mark; fl6.flowi6_uid = sock_net_uid(net, NULL);