Commit aea23c32 authored Jul 07, 2020 by David Ahern Committed by David S. Miller Jul 07, 2020

ipv6: Fix use of anycast address with loopback



Thomas reported a regression with IPv6 and anycast using the following
reproducer:

    echo 1 >  /proc/sys/net/ipv6/conf/all/forwarding
    ip -6 a add fc12::1/16 dev lo
    sleep 2
    echo "pinging lo"
    ping6 -c 2 fc12::

The conversion of addrconf_f6i_alloc to use ip6_route_info_create missed
the use of fib6_is_reject which checks addresses added to the loopback
interface and sets the REJECT flag as needed. Update fib6_is_reject for
loopback checks to handle RTF_ANYCAST addresses.

Fixes: c7a1ce39 ("ipv6: Change addrconf_f6i_alloc to use ip6_route_info_create")
Reported-by:  <thomas.gambier@nexedi.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent f815dd5c

net/ipv6/route.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -3405,7 +3405,7 @@ static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
		if ((flags & RTF_REJECT) \|\|
		(dev && (dev->flags & IFF_LOOPBACK) &&
		!(addr_type & IPV6_ADDR_LOOPBACK) &&
		!(flags & RTF_LOCAL)))
		!(flags & (RTF_ANYCAST \| RTF_LOCAL))))
		return true;

		return false;

Admin message