diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-07-13 13:52:01 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-07-15 11:49:55 +0100 |
| commit | 88d78bc097cd8ebc6541e93316c9d9bf651b13e8 (patch) | |
| tree | c76a6a482e4b6238c272aac7170c9b99491f3629 | |
| parent | f47d00e077e7d61baf69e46dde3210c886360207 (diff) | |
tcp: Fix data-races around sysctl_tcp_base_mss.
While reading sysctl_tcp_base_mss, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
Fixes: 5d424d5a674f ("[TCP]: MTU probing")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/ipv4/tcp_output.c | 2 | ||||
| -rw-r--r-- | net/ipv4/tcp_timer.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 3fcfc0f1e9f9..9450d8469871 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1765,7 +1765,7 @@ void tcp_mtup_init(struct sock *sk) icsk->icsk_mtup.enabled = READ_ONCE(net->ipv4.sysctl_tcp_mtu_probing) > 1; icsk->icsk_mtup.search_high = tp->rx_opt.mss_clamp + sizeof(struct tcphdr) + icsk->icsk_af_ops->net_header_len; - icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, net->ipv4.sysctl_tcp_base_mss); + icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, READ_ONCE(net->ipv4.sysctl_tcp_base_mss)); icsk->icsk_mtup.probe_size = 0; if (icsk->icsk_mtup.enabled) icsk->icsk_mtup.probe_timestamp = tcp_jiffies32; diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 98bb00e29e1e..04063c7e33ba 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -171,7 +171,7 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk) icsk->icsk_mtup.probe_timestamp = tcp_jiffies32; } else { mss = tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low) >> 1; - mss = min(net->ipv4.sysctl_tcp_base_mss, mss); + mss = min(READ_ONCE(net->ipv4.sysctl_tcp_base_mss), mss); mss = max(mss, net->ipv4.sysctl_tcp_mtu_probe_floor); mss = max(mss, net->ipv4.sysctl_tcp_min_snd_mss); icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss); |