From 8ce44cf35ef6e8ddfc352d73f1eb67bb539f8146 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 19 Jul 2023 21:28:47 +0000 Subject: [PATCH] tcp: annotate data-races around tp->tcp_tx_delay [ Upstream commit 348b81b68b13ebd489a3e6a46aa1c384c731c919 ] do_tcp_getsockopt() reads tp->tcp_tx_delay while another cpu might change its value. Fixes: a842fe1425cb ("tcp: add optional per socket transmit delay") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230719212857.3943972-2-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/tcp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index fdf2ddc4864d..e33abcff5608 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3177,7 +3177,7 @@ static int do_tcp_setsockopt(struct sock *sk, int level, case TCP_TX_DELAY: if (val) tcp_enable_tx_delay(); - tp->tcp_tx_delay = val; + WRITE_ONCE(tp->tcp_tx_delay, val); break; default: err = -ENOPROTOOPT; @@ -3634,7 +3634,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level, break; case TCP_TX_DELAY: - val = tp->tcp_tx_delay; + val = READ_ONCE(tp->tcp_tx_delay); break; case TCP_TIMESTAMP: