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authorEric Dumazet <edumazet@google.com>2023-07-19 21:28:52 +0000
committerJakub Kicinski <kuba@kernel.org>2023-07-20 12:34:18 -0700
commit3a037f0f3c4bfe44518f2fbb478aa2f99a9cd8bb (patch)
tree2f5d3a67231c9e4f1ca93e4458b4ccfb0554efe6
parent6e5e1de616bf5f3df1769abc9292191dfad9110a (diff)
tcp: annotate data-races around icsk->icsk_syn_retries
do_tcp_getsockopt() and reqsk_timer_handler() read icsk->icsk_syn_retries while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20230719212857.3943972-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--net/ipv4/inet_connection_sock.c2
-rw-r--r--net/ipv4/tcp.c6
2 files changed, 4 insertions, 4 deletions
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 0cc19cfbb673..aeebe8816689 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -1019,7 +1019,7 @@ static void reqsk_timer_handler(struct timer_list *t)
icsk = inet_csk(sk_listener);
net = sock_net(sk_listener);
- max_syn_ack_retries = icsk->icsk_syn_retries ? :
+ max_syn_ack_retries = READ_ONCE(icsk->icsk_syn_retries) ? :
READ_ONCE(net->ipv4.sysctl_tcp_synack_retries);
/* Normally all the openreqs are young and become mature
* (i.e. converted to established socket) for first timeout.
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 574fd0da1673..9f74ac16f1c1 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3291,7 +3291,7 @@ int tcp_sock_set_syncnt(struct sock *sk, int val)
return -EINVAL;
lock_sock(sk);
- inet_csk(sk)->icsk_syn_retries = val;
+ WRITE_ONCE(inet_csk(sk)->icsk_syn_retries, val);
release_sock(sk);
return 0;
}
@@ -3572,7 +3572,7 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
if (val < 1 || val > MAX_TCP_SYNCNT)
err = -EINVAL;
else
- icsk->icsk_syn_retries = val;
+ WRITE_ONCE(icsk->icsk_syn_retries, val);
break;
case TCP_SAVE_SYN:
@@ -3993,7 +3993,7 @@ int do_tcp_getsockopt(struct sock *sk, int level,
val = keepalive_probes(tp);
break;
case TCP_SYNCNT:
- val = icsk->icsk_syn_retries ? :
+ val = READ_ONCE(icsk->icsk_syn_retries) ? :
READ_ONCE(net->ipv4.sysctl_tcp_syn_retries);
break;
case TCP_LINGER2: