From de9490c32bc10020efdd1509689a28f197d6dfb8 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 11 Jul 2022 17:15:26 -0700 Subject: [PATCH] icmp: Fix a data-race around sysctl_icmp_errors_use_inbound_ifaddr. [ Upstream commit d2efabce81db7eed1c98fa1a3f203f0edd738ac3 ] While reading sysctl_icmp_errors_use_inbound_ifaddr, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 1c2fb7f93cb2 ("[IPV4]: Sysctl configurable icmp error source address.") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/ipv4/icmp.c | 2 +- net/ipv4/sysctl_net_ipv4.c | 2 ++ 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 6f444b2..e40a79b 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -702,7 +702,7 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info, rcu_read_lock(); if (rt_is_input_route(rt) && - net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr) + READ_ONCE(net->ipv4.sysctl_icmp_errors_use_inbound_ifaddr)) dev = dev_get_by_index_rcu(net, inet_iif(skb_in)); if (dev) diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 5186303..49a8167 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -648,6 +648,8 @@ static struct ctl_table ipv4_net_table[] = { .maxlen = sizeof(u8), .mode = 0644, .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE }, { .procname = "icmp_ratelimit", -- 2.7.4