From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit 26023e91e12c68669db416b97234328a03d8e499 ]
This field can be read locklessly from do_tcp_getsockopt()
Fixes: dca43c75e7e5 ("tcp: Add TCP_USER_TIMEOUT socket option.")
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230719212857.3943972-11-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv4/tcp.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 8a441dfd258d5..0a5f61b3423bf 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3081,7 +3081,7 @@ EXPORT_SYMBOL(tcp_sock_set_syncnt);
void tcp_sock_set_user_timeout(struct sock *sk, u32 val)
{
lock_sock(sk);
- inet_csk(sk)->icsk_user_timeout = val;
+ WRITE_ONCE(inet_csk(sk)->icsk_user_timeout, val);
release_sock(sk);
}
EXPORT_SYMBOL(tcp_sock_set_user_timeout);
@@ -3393,7 +3393,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname,
if (val < 0)
err = -EINVAL;
else
- icsk->icsk_user_timeout = val;
+ WRITE_ONCE(icsk->icsk_user_timeout, val);
break;
case TCP_FASTOPEN:
@@ -3890,7 +3890,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level,
break;
case TCP_USER_TIMEOUT:
- val = icsk->icsk_user_timeout;
+ val = READ_ONCE(icsk->icsk_user_timeout);
break;
case TCP_FASTOPEN:
--
2.39.2
