From: Kuniyuki Iwashima kuniyu@amazon.com
[ Upstream commit 4785a66702f086cf2ea84bdbe6ec921f274bd9f2 ]
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 kuniyu@amazon.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c | 2 +- net/ipv4/syncookies.c | 2 +- net/ipv4/sysctl_net_ipv4.c | 2 ++ net/ipv4/tcp_input.c | 2 +- net/ipv4/tcp_output.c | 2 +- 5 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c index 4af5561cbfc5..7c760aa65540 100644 --- a/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c +++ b/drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c @@ -1392,7 +1392,7 @@ static void chtls_pass_accept_request(struct sock *sk, th_ecn = tcph->ece && tcph->cwr; if (th_ecn) { ect = !INET_ECN_is_not_ect(ip_dsfield); - ecn_ok = sock_net(sk)->ipv4.sysctl_tcp_ecn; + ecn_ok = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_ecn); if ((!ect && ecn_ok) || tcp_ca_needs_ecn(sk)) inet_rsk(oreq)->ecn_ok = 1; } diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index f33c31dd7366..b387c4835155 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -273,7 +273,7 @@ bool cookie_ecn_ok(const struct tcp_options_received *tcp_opt, if (!ecn_ok) return false;
- if (net->ipv4.sysctl_tcp_ecn) + if (READ_ONCE(net->ipv4.sysctl_tcp_ecn)) return true;
return dst_feature(dst, RTAX_FEATURE_ECN); diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 33e65e79e46e..11add5214713 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -680,6 +680,8 @@ static struct ctl_table ipv4_net_table[] = { .maxlen = sizeof(u8), .mode = 0644, .proc_handler = proc_dou8vec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_TWO, }, { .procname = "tcp_ecn_fallback", diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 6b8fcf79688b..2d71bcfcc759 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -6712,7 +6712,7 @@ static void tcp_ecn_create_request(struct request_sock *req,
ect = !INET_ECN_is_not_ect(TCP_SKB_CB(skb)->ip_dsfield); ecn_ok_dst = dst_feature(dst, DST_FEATURE_ECN_MASK); - ecn_ok = net->ipv4.sysctl_tcp_ecn || ecn_ok_dst; + ecn_ok = READ_ONCE(net->ipv4.sysctl_tcp_ecn) || ecn_ok_dst;
if (((!ect || th->res1) && ecn_ok) || tcp_ca_needs_ecn(listen_sk) || (ecn_ok_dst & DST_FEATURE_ECN_CA) || diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 6b00c17c72aa..9eefe7f6370f 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) {