From 30ca22e4a5d0063dd9a9cdf35cd139c5807cbeb3 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Wed, 2 May 2018 22:41:56 +0300 Subject: [PATCH] ipv6: Revert "ipv6: Allow non-gateway ECMP for IPv6" This reverts commit edd7ceb78296 ("ipv6: Allow non-gateway ECMP for IPv6"). Eric reported a division by zero in rt6_multipath_rebalance() which is caused by above commit that considers identical local routes to be siblings. The division by zero happens because a nexthop weight is not set for local routes. Revert the commit as it does not fix a bug and has side effects. To reproduce: # ip -6 address add 2001:db8::1/64 dev dummy0 # ip -6 address add 2001:db8::1/64 dev dummy1 Fixes: edd7ceb78296 ("ipv6: Allow non-gateway ECMP for IPv6") Signed-off-by: Ido Schimmel Reported-by: Eric Dumazet Tested-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/ip6_route.h | 3 ++- net/ipv6/ip6_fib.c | 3 +++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index abceb5864d99..08b132381984 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -68,7 +68,8 @@ static inline bool rt6_need_strict(const struct in6_addr *daddr) static inline bool rt6_qualify_for_ecmp(const struct rt6_info *rt) { - return (rt->rt6i_flags & (RTF_ADDRCONF | RTF_DYNAMIC)) == 0; + return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) == + RTF_GATEWAY; } void ip6_route_input(struct sk_buff *skb); diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index 3c97c29d4401..deab2db6692e 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -934,6 +934,9 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, * list. * Only static routes (which don't have flag * RTF_EXPIRES) are used for ECMPv6. + * + * To avoid long list, we only had siblings if the + * route have a gateway. */ if (rt_can_ecmp && rt6_qualify_for_ecmp(iter)) -- 2.30.2