From: Eric Dumazet Date: Wed, 19 Jul 2023 21:28:54 +0000 (+0000) Subject: tcp: annotate data-races around rskq_defer_accept X-Git-Tag: v5.15.123~9 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4f0a31f7325865a0a76a89cc06e9021965f82cf7;p=thirdparty%2Fkernel%2Fstable.git tcp: annotate data-races around rskq_defer_accept [ Upstream commit ae488c74422fb1dcd807c0201804b3b5e8a322a3 ] do_tcp_getsockopt() reads rskq_defer_accept while another cpu might change its value. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230719212857.3943972-9-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 58f202fd6f269..29661f7e372d9 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3599,9 +3599,9 @@ static int do_tcp_setsockopt(struct sock *sk, int level, int optname, case TCP_DEFER_ACCEPT: /* Translate value in seconds to number of retransmits */ - icsk->icsk_accept_queue.rskq_defer_accept = - secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, - TCP_RTO_MAX / HZ); + WRITE_ONCE(icsk->icsk_accept_queue.rskq_defer_accept, + secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ, + TCP_RTO_MAX / HZ)); break; case TCP_WINDOW_CLAMP: @@ -4000,8 +4000,9 @@ static int do_tcp_getsockopt(struct sock *sk, int level, 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, - TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ); + val = READ_ONCE(icsk->icsk_accept_queue.rskq_defer_accept); + val = retrans_to_secs(val, TCP_TIMEOUT_INIT / HZ, + TCP_RTO_MAX / HZ); break; case TCP_WINDOW_CLAMP: val = tp->window_clamp;