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 E72603F1661; Wed, 20 May 2026 17:44:00 +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=1779299042; cv=none; b=DjGG3BLEQ65N9xDvK+PUOm+KU/U1VTfoqeJxIyzWmF9DwW6fev3YyWuHMXBL+9N8w+4OAzqaJ21JAddY2QXXYlE7VM+gkyigHVj2IwxpiVJvrQ+I/u7Op+t8N/ToRJt1Z/XXwlbMi4P1VcEsEyx2ZD8PW22poD33nh6KDxbQ6gM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299042; c=relaxed/simple; bh=9Kh7dkfiXnyfpH5AC5TzWJsNdjlYzMcSIwCz3d0LrKc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qU2/0larZKqAaGXBQHQR14JrDupCLrT7ieQs7339ZCb+YxQvocK8An2JCYXOwO5DWjaC5wwlyqRNgfQ2VwJrWl6L9MQC6SeFmRI4Wf/DXTL9HnwplKWiCgyF/EKEsP/wfrEzydFkMM7ErzSRDGytJRGNPYS9uxkYn0tQX10k5yE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fWoZxhQi; 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="fWoZxhQi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7FD1F1F000E9; Wed, 20 May 2026 17:44:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779299040; bh=Gp8GTA3hklJlcRXxT/lNQBWmKFo2N3TkFCOR6RoJbUM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fWoZxhQipyiTbdr+g2i1ISufDbcq2e6SXqKjW4F8QwaVHWwCHdMVxX2vJ5GqPrFE1 ctCjiHDnr2qR9T6ykCuVmeQN6zaiY7otmFbAycf1Zv57n+Q2mzwPz9hKkddVPif5vf GO7i9KRNFY7eZc1vYe36M7liJ9spuDsK34EODHJw= 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 6.18 640/957] tcp: annotate data-races around tp->reord_seen Date: Wed, 20 May 2026 18:18:43 +0200 Message-ID: <20260520162148.408051789@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: stable@vger.kernel.org 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 62585690e6b2a112c408fe25f142b246ac833c42 ] tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: 7ec65372ca53 ("tcp: add stat of data packet reordering events") Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260416200319.3608680-11-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/tcp.c | 2 +- net/ipv4/tcp_input.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 3a5801ba3df1a..03299c21e4d68 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4418,7 +4418,7 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk, nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, 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, tp->reord_seen); + 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_u16(stats, TCP_NLA_TIMEOUT_REHASH, tp->timeout_rehash); nla_put_u32(stats, TCP_NLA_BYTES_NOTSENT, diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 90727e1e581e4..5a944b1ec320c 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1266,7 +1266,7 @@ static void tcp_check_sack_reordering(struct sock *sk, const u32 low_seq, } /* This exciting event is worth to be remembered. 8) */ - tp->reord_seen++; + WRITE_ONCE(tp->reord_seen, tp->reord_seen + 1); NET_INC_STATS(sock_net(sk), ts ? LINUX_MIB_TCPTSREORDER : LINUX_MIB_TCPSACKREORDER); } @@ -2224,7 +2224,7 @@ static void tcp_check_reno_reordering(struct sock *sk, const int addend) WRITE_ONCE(tp->reordering, min_t(u32, tp->packets_out + addend, READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering))); - tp->reord_seen++; + WRITE_ONCE(tp->reord_seen, tp->reord_seen + 1); NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRENOREORDER); } -- 2.53.0