From 4785a66702f086cf2ea84bdbe6ec921f274bd9f2 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 11 Jul 2022 17:15:30 -0700 Subject: tcp: Fix data-races around sysctl_tcp_ecn. While reading sysctl_tcp_ecn, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp_output.c') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 1c054431e358..3dc17551ce25 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -324,7 +324,7 @@ static void tcp_ecn_send_syn(struct sock *sk, struct sk_buff *skb) { struct tcp_sock *tp = tcp_sk(sk); bool bpf_needs_ecn = tcp_bpf_ca_needs_ecn(sk); - bool use_ecn = sock_net(sk)->ipv4.sysctl_tcp_ecn == 1 || + bool use_ecn = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_ecn) == 1 || tcp_ca_needs_ecn(sk) || bpf_needs_ecn; if (!use_ecn) { -- cgit From 12b8d9ca7e678abc48195294494f1815b555d658 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Mon, 11 Jul 2022 17:15:31 -0700 Subject: tcp: Fix a data-race around sysctl_tcp_ecn_fallback. While reading sysctl_tcp_ecn_fallback, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 492135557dc0 ("tcp: add rfc3168, section 6.1.1.1. fallback") Signed-off-by: Kuniyuki Iwashima Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/tcp_output.c') diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 3dc17551ce25..11aa0ab10bba 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -346,7 +346,7 @@ static void tcp_ecn_send_syn(struct sock *sk, struct sk_buff *skb) static void tcp_ecn_clear_syn(struct sock *sk, struct sk_buff *skb) { - if (sock_net(sk)->ipv4.sysctl_tcp_ecn_fallback) + if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_ecn_fallback)) /* tp->ecn_flags are cleared at a later point in time when * SYN ACK is ultimatively being received. */ -- cgit