From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv4/fib_semantics.c | 2 +-
net/ipv4/nexthop.c | 5 +++--
net/ipv6/route.c | 2 +-
3 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index a98350dacbc3..674694d8ac61 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1829,7 +1829,7 @@ int fib_dump_info(struct sk_buff *skb, u32 portid, u32 seq, int event,
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;
}
diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 5dbd4b5505eb..cc8f120149f6 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -1857,7 +1857,7 @@ static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
/* __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));
}
}
@@ -2362,7 +2362,8 @@ static int insert_nexthop(struct net *net, struct nexthop *new_nh,
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);
}
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 4ca754c360a3..27274fc3619a 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -5756,7 +5756,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb,
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;
--
2.35.1
