From: Eric Dumazet edumazet@google.com
[ 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@google.com Link: https://lore.kernel.org/r/20230719212857.3943972-11-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 4556ba6e7d74d..c9b955d9d7ace 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3409,7 +3409,7 @@ 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); @@ -3729,7 +3729,7 @@ 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: @@ -4250,7 +4250,7 @@ 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: