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authorKuniyuki Iwashima <kuniyu@amazon.com>2022-07-15 19:17:54 +0200
committerDavid S. Miller <davem@davemloft.net>2022-07-18 13:21:54 +0200
commit5a54213318c43f4009ae158347aa6016e3b9b55a (patch)
tree35efe5034a35dcd8dbee8b0d93d7c03b48dc2d87 /net/ipv4/tcp_fastopen.c
parenttcp: Fix data-races around sysctl_max_syn_backlog. (diff)
downloadlinux-5a54213318c43f4009ae158347aa6016e3b9b55a.tar.xz
linux-5a54213318c43f4009ae158347aa6016e3b9b55a.zip
tcp: Fix data-races around sysctl_tcp_fastopen.
While reading sysctl_tcp_fastopen, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: 2100c8d2d9db ("net-tcp: Fast Open base") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Yuchung Cheng <ycheng@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_fastopen.c')
-rw-r--r--net/ipv4/tcp_fastopen.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index fdbcf2a6d08e..0acdb5473850 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -332,7 +332,7 @@ static bool tcp_fastopen_no_cookie(const struct sock *sk,
const struct dst_entry *dst,
int flag)
{
- return (sock_net(sk)->ipv4.sysctl_tcp_fastopen & flag) ||
+ return (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen) & flag) ||
tcp_sk(sk)->fastopen_no_cookie ||
(dst && dst_metric(dst, RTAX_FASTOPEN_NO_COOKIE));
}
@@ -347,7 +347,7 @@ struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb,
const struct dst_entry *dst)
{
bool syn_data = TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq + 1;
- int tcp_fastopen = sock_net(sk)->ipv4.sysctl_tcp_fastopen;
+ int tcp_fastopen = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fastopen);
struct tcp_fastopen_cookie valid_foc = { .len = -1 };
struct sock *child;
int ret = 0;