icmp: Fix a data-race around sysctl_icmp_ratelimit.

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

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index a49b68d6b969892d63f43dc8faaca2be32ad9137..1d454cc41713c79842ea7c5970c5f5202483d197 100644 (file)
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -320,7 +320,8 @@ static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
 
        vif = l3mdev_master_ifindex(dst->dev);
        peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, vif, 1);
-       rc = inet_peer_xrlim_allow(peer, net->ipv4.sysctl_icmp_ratelimit);
+       rc = inet_peer_xrlim_allow(peer,
+                                  READ_ONCE(net->ipv4.sysctl_icmp_ratelimit));
        if (peer)
                inet_putpeer(peer);
 out: