nexthop: Fix data-races around nexthop_compat_mode.

[ Upstream commit bdf00bf24bef9be1ca641a6390fd5487873e0d2e ]

While reading nexthop_compat_mode, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 4f80116d3d ("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>
This commit is contained in:
Kuniyuki Iwashima
2022-07-11 17:15:33 -07:00
committed by Greg Kroah-Hartman
parent 2c56958de8
commit a51040d4b1
3 changed files with 5 additions and 4 deletions

View File

@@ -5641,7 +5641,7 @@ 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;