From: Kuniyuki Iwashima kuniyu@amazon.com
[ Upstream commit 39e24435a776e9de5c6dd188836cf2523547804b ]
While reading these sysctl knobs, they can be changed concurrently. Thus, we need to add READ_ONCE() to their readers.
- tcp_retries1 - tcp_retries2 - tcp_orphan_retries - tcp_fin_timeout
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 --- include/net/tcp.h | 3 ++- net/ipv4/tcp.c | 2 +- net/ipv4/tcp_output.c | 2 +- net/ipv4/tcp_timer.c | 10 +++++----- 4 files changed, 9 insertions(+), 8 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h index 5c5807ed66ee..f92b93cf074c 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1430,7 +1430,8 @@ static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp)
static inline int tcp_fin_time(const struct sock *sk) { - int fin_timeout = tcp_sk(sk)->linger2 ? : sock_net(sk)->ipv4.sysctl_tcp_fin_timeout; + int fin_timeout = tcp_sk(sk)->linger2 ? : + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fin_timeout); const int rto = inet_csk(sk)->icsk_rto;
if (fin_timeout < (rto << 2) - (rto >> 1)) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index b1b121d5076c..0f89d0f2c21f 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3386,7 +3386,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level, case TCP_LINGER2: val = tp->linger2; if (val >= 0) - val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ; + val = (val ? : READ_ONCE(net->ipv4.sysctl_tcp_fin_timeout)) / HZ; break; case TCP_DEFER_ACCEPT: val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept, diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 33f9a486661c..3d5ea169e905 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3776,7 +3776,7 @@ void tcp_send_probe0(struct sock *sk) }
if (err <= 0) { - if (icsk->icsk_backoff < net->ipv4.sysctl_tcp_retries2) + if (icsk->icsk_backoff < READ_ONCE(net->ipv4.sysctl_tcp_retries2)) icsk->icsk_backoff++; icsk->icsk_probes_out++; probe_max = TCP_RTO_MAX; diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 5d761333ffc4..e905fff09fea 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -124,7 +124,7 @@ static int tcp_out_of_resources(struct sock *sk, bool do_reset) */ static int tcp_orphan_retries(struct sock *sk, bool alive) { - int retries = sock_net(sk)->ipv4.sysctl_tcp_orphan_retries; /* May be zero. */ + int retries = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_orphan_retries); /* May be zero. */
/* We know from an ICMP that something is wrong. */ if (sk->sk_err_soft && !alive) @@ -226,7 +226,7 @@ static int tcp_write_timeout(struct sock *sk) retry_until = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries; expired = icsk->icsk_retransmits >= retry_until; } else { - if (retransmits_timed_out(sk, net->ipv4.sysctl_tcp_retries1, 0)) { + if (retransmits_timed_out(sk, READ_ONCE(net->ipv4.sysctl_tcp_retries1), 0)) { /* Black hole detection */ tcp_mtu_probing(icsk, sk);
@@ -235,7 +235,7 @@ static int tcp_write_timeout(struct sock *sk) sk_rethink_txhash(sk); }
- retry_until = net->ipv4.sysctl_tcp_retries2; + retry_until = READ_ONCE(net->ipv4.sysctl_tcp_retries2); if (sock_flag(sk, SOCK_DEAD)) { const bool alive = icsk->icsk_rto < TCP_RTO_MAX;
@@ -362,7 +362,7 @@ static void tcp_probe_timer(struct sock *sk) (s32)(tcp_time_stamp(tp) - start_ts) > icsk->icsk_user_timeout) goto abort;
- max_probes = sock_net(sk)->ipv4.sysctl_tcp_retries2; + max_probes = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_retries2); if (sock_flag(sk, SOCK_DEAD)) { const bool alive = inet_csk_rto_backoff(icsk, TCP_RTO_MAX) < TCP_RTO_MAX;
@@ -556,7 +556,7 @@ void tcp_retransmit_timer(struct sock *sk) } inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, tcp_clamp_rto_to_user_timeout(sk), TCP_RTO_MAX); - if (retransmits_timed_out(sk, net->ipv4.sysctl_tcp_retries1 + 1, 0)) + if (retransmits_timed_out(sk, READ_ONCE(net->ipv4.sysctl_tcp_retries1) + 1, 0)) __sk_dst_reset(sk);
out:;