diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-07-15 19:17:46 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-07-18 13:21:54 +0200 |
| commit | 20a3b1c0f603e8c55c3396abd12dfcfb523e4d3c (patch) | |
| tree | de4a9c1b28887f2a09cdbb7b087a8f1005b51bde /net/ipv4/tcp_timer.c | |
| parent | tcp: Fix data-races around keepalive sysctl knobs. (diff) | |
| download | linux-20a3b1c0f603e8c55c3396abd12dfcfb523e4d3c.tar.xz linux-20a3b1c0f603e8c55c3396abd12dfcfb523e4d3c.zip | |
tcp: Fix data-races around sysctl_tcp_syn(ack)?_retries.
While reading sysctl_tcp_syn(ack)?_retries, they can be changed
concurrently. Thus, we need to add READ_ONCE() to their 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>
Diffstat (limited to '')
| -rw-r--r-- | net/ipv4/tcp_timer.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 4f3b9ab222b6..a234704e8163 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -239,7 +239,8 @@ static int tcp_write_timeout(struct sock *sk) if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { if (icsk->icsk_retransmits) __dst_negative_advice(sk); - retry_until = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries; + retry_until = icsk->icsk_syn_retries ? : + READ_ONCE(net->ipv4.sysctl_tcp_syn_retries); expired = icsk->icsk_retransmits >= retry_until; } else { if (retransmits_timed_out(sk, net->ipv4.sysctl_tcp_retries1, 0)) { @@ -406,12 +407,15 @@ abort: tcp_write_err(sk); static void tcp_fastopen_synack_timer(struct sock *sk, struct request_sock *req) { struct inet_connection_sock *icsk = inet_csk(sk); - int max_retries = icsk->icsk_syn_retries ? : - sock_net(sk)->ipv4.sysctl_tcp_synack_retries + 1; /* add one more retry for fastopen */ struct tcp_sock *tp = tcp_sk(sk); + int max_retries; req->rsk_ops->syn_ack_timeout(req); + /* add one more retry for fastopen */ + max_retries = icsk->icsk_syn_retries ? : + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_synack_retries) + 1; + if (req->num_timeout >= max_retries) { tcp_write_err(sk); return; |