From: David Ahern <dsahern@xxxxxxxxx> [ Upstream commit 1869e226a7b3ef75b4f70ede2f1b7229f7157fa4 ] flowi4_multipath_hash was added by the commit referenced below for tunnels. Unfortunately, the patch did not initialize the new field for several fast path lookups that do not initialize the entire flow struct to 0. Fix those locations. Currently, flowi4_multipath_hash is random garbage and affects the hash value computed by fib_multipath_hash for multipath selection. Fixes: 24ba14406c5c ("route: Add multipath_hash in flowi_common to make user-define hash") Signed-off-by: David Ahern <dsahern@xxxxxxxxx> Cc: wenxu <wenxu@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/net/flow.h | 1 + net/core/filter.c | 1 + net/ipv4/fib_frontend.c | 1 + net/ipv4/route.c | 1 + 4 files changed, 4 insertions(+) --- a/include/net/flow.h +++ b/include/net/flow.h @@ -116,6 +116,7 @@ static inline void flowi4_init_output(st fl4->saddr = saddr; fl4->fl4_dport = dport; fl4->fl4_sport = sport; + fl4->flowi4_multipath_hash = 0; } /* Reset some input parameters after previous lookup */ --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4650,6 +4650,7 @@ static int bpf_ipv4_fib_lookup(struct ne fl4.saddr = params->ipv4_src; fl4.fl4_sport = params->sport; fl4.fl4_dport = params->dport; + fl4.flowi4_multipath_hash = 0; if (flags & BPF_FIB_LOOKUP_DIRECT) { u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -372,6 +372,7 @@ static int __fib_validate_source(struct fl4.flowi4_tun_key.tun_id = 0; fl4.flowi4_flags = 0; fl4.flowi4_uid = sock_net_uid(net, NULL); + fl4.flowi4_multipath_hash = 0; no_addr = idev->ifa_list == NULL; --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2104,6 +2104,7 @@ static int ip_route_input_slow(struct sk fl4.daddr = daddr; fl4.saddr = saddr; fl4.flowi4_uid = sock_net_uid(net, NULL); + fl4.flowi4_multipath_hash = 0; if (fib4_rules_early_flow_dissect(net, skb, &fl4, &_flkeys)) { flkeys = &_flkeys;