From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 69FB33F20FA; Wed, 20 May 2026 17:44:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299047; cv=none; b=Dw4imU20e73iz6d1ebKta2OXArt5xhBLZt6lZGyUzyTNp3Y6szbr6DyvtZzW0c3Yl+8ItawcEDWKtlH/qZweS0D4mudnAqBW3m9B/Zgo0v+DbwAGrP5GeGnjY3r0RoMDeI7X0vQUrHXr3VrfXCvwAvwV2SR4UBmYyXYtFCuIvtE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299047; c=relaxed/simple; bh=yoyCm9/yAle6/x7GpmTPkMaKimUXxIC8d9Z94e6y3Po=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FmLTPU0X1Q2whEEpbvv3I2YCwMUImWggXeEeW7NU/i/auhDHvCDLAypEitp6XxVPGaO8ilADGhQvzEbt9bnXiPuCX2IeNGEPkj5IuXSJYbNDTuScg4J0Z9kJNlEPbBqVwTS9qFMpd5HSG59L2Ef1RJxs61+m1SijfLeLTUQinag= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AAsPWcGc; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="AAsPWcGc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B6FE1F000E9; Wed, 20 May 2026 17:44:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779299046; bh=v7g5aOc+STugu9tT8MkOQR+eXydSY9pzy5kMalTj9E4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=AAsPWcGcubFAHWOHbAeJuF4ZGs59wiT2FxAS+ZrB4UKifDQAiixTQmG7WHLAvLtT+ bZavGmUe7s/xVvT84yMSenmjQTBu7Qv55viMkok2UX08DwOQRyBdqftHMYeSnBCmxK YDbn6e2S+9TO6XLf/uEoZvsXxNfVb7cy1MCJi/ws= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.18 642/957] tcp: annotate data-races around tp->srtt_us Date: Wed, 20 May 2026 18:18:45 +0200 Message-ID: <20260520162148.450333161@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162134.554764788@linuxfoundation.org> References: <20260520162134.554764788@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 290b693ce7c9d48588d88b15a782a3efc6fa036b ] tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: e8bd8fca6773 ("tcp: add SRTT to SCM_TIMESTAMPING_OPT_STATS") Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260416200319.3608680-12-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/tcp.c | 5 +++-- net/ipv4/tcp_input.c | 2 +- 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 2e62441515fee..a799329281532 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3605,7 +3605,8 @@ static void tcp_enable_tx_delay(struct sock *sk, int val) if (delta && sk->sk_state == TCP_ESTABLISHED) { s64 srtt = (s64)tp->srtt_us + delta; - tp->srtt_us = clamp_t(s64, srtt, 1, ~0U); + WRITE_ONCE(tp->srtt_us, + clamp_t(s64, srtt, 1, ~0U)); /* Note: does not deal with non zero icsk_backoff */ tcp_set_rto(sk); @@ -4442,7 +4443,7 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk, READ_ONCE(tp->bytes_retrans), TCP_NLA_PAD); nla_put_u32(stats, TCP_NLA_DSACK_DUPS, READ_ONCE(tp->dsack_dups)); nla_put_u32(stats, TCP_NLA_REORD_SEEN, READ_ONCE(tp->reord_seen)); - nla_put_u32(stats, TCP_NLA_SRTT, tp->srtt_us >> 3); + nla_put_u32(stats, TCP_NLA_SRTT, READ_ONCE(tp->srtt_us) >> 3); nla_put_u16(stats, TCP_NLA_TIMEOUT_REHASH, tp->timeout_rehash); nla_put_u32(stats, TCP_NLA_BYTES_NOTSENT, max_t(int, 0, tp->write_seq - tp->snd_nxt)); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index e8ba52c908da1..5fb5f3f6393c1 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1099,7 +1099,7 @@ static void tcp_rtt_estimator(struct sock *sk, long mrtt_us) tcp_bpf_rtt(sk, mrtt_us, srtt); } - tp->srtt_us = max(1U, srtt); + WRITE_ONCE(tp->srtt_us, max(1U, srtt)); } void tcp_update_pacing_rate(struct sock *sk) -- 2.53.0