From: Kuniyuki Iwashima kuniyu@amazon.com
[ Upstream commit bdf00bf24bef9be1ca641a6390fd5487873e0d2e ]
While reading nexthop_compat_mode, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: 4f80116d3df3 ("net: ipv4: add sysctl for nexthop api compatibility mode") Signed-off-by: Kuniyuki Iwashima kuniyu@amazon.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/fib_semantics.c | 2 +- net/ipv4/nexthop.c | 5 +++-- net/ipv6/route.c | 2 +- 3 files changed, 5 insertions(+), 4 deletions(-)
--- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -1831,7 +1831,7 @@ int fib_dump_info(struct sk_buff *skb, u goto nla_put_failure; if (nexthop_is_blackhole(fi->nh)) rtm->rtm_type = RTN_BLACKHOLE; - if (!fi->fib_net->ipv4.sysctl_nexthop_compat_mode) + if (!READ_ONCE(fi->fib_net->ipv4.sysctl_nexthop_compat_mode)) goto offload; }
--- a/net/ipv4/nexthop.c +++ b/net/ipv4/nexthop.c @@ -882,7 +882,7 @@ static void __remove_nexthop_fib(struct /* __ip6_del_rt does a release, so do a hold here */ fib6_info_hold(f6i); ipv6_stub->ip6_del_rt(net, f6i, - !net->ipv4.sysctl_nexthop_compat_mode); + !READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode)); } }
@@ -1194,7 +1194,8 @@ out: if (!rc) { nh_base_seq_inc(net); nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo); - if (replace_notify && net->ipv4.sysctl_nexthop_compat_mode) + if (replace_notify && + READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode)) nexthop_replace_notify(net, new_nh, &cfg->nlinfo); }
--- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -5641,7 +5641,7 @@ static int rt6_fill_node(struct net *net if (nexthop_is_blackhole(rt->nh)) rtm->rtm_type = RTN_BLACKHOLE;
- if (net->ipv4.sysctl_nexthop_compat_mode && + if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) && rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0) goto nla_put_failure;