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 AEF99348C55; Wed, 20 May 2026 18:19:27 +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=1779301168; cv=none; b=ZsHbN/IjNEWi/OlxaHlaC9X07DTErvIYFJJTHYj80BGfHlT50aZ7Js3eVRn9+oGGiCC5AuXSIueToK9Jb/UaYRZBYkb0q2XIHFscaLQ6TCUzmgre80XBN9kh052zgJc81wXHbxWDeDFv+8EZv/iBmppcCgR+TYsYKvho4xUdQtQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779301168; c=relaxed/simple; bh=C7FoEOG+EkFGSvQENtXAAgD5W2iUz/KGHeFRu0gIV8U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JteZh7U8H/CVylFOBmxB2GC0ITY0IXuT4gvJ9f2VamYywhfb0bg9gaEsHgoauphDGR6d4Tb4pfIarp8mtlXdLONDwCRuUlkp4rGcRF94nzSBgigVfwH10rjKhfP6ducTObqran1Wwh9f7lVOT1ZDQMph/N1HPbDCGkDCUILqY20= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=VbYzsTJu; 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="VbYzsTJu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 21D071F000E9; Wed, 20 May 2026 18:19:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779301167; bh=PV93MHFjftA0TIx+MPoKVAS433ZKiLNpG/kKFXZSKfw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=VbYzsTJu7+IYCgmk16iYmmw6gDGN5tFUE0q/jbc8wOXe9tl6X1ATu04bYI52kY9jM 4Dmf2a+CgrEqbXMAD/SH5Zi2qsYfP4LfY2CfBMRKWQQPXxSDdt+rPWK4vZazHmE4MZ CPMzHP+DaN2JzqCunpI9HTEv2oVZ9Q8Io581gnX0= 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 6.12 452/666] tcp: annotate data-races around tp->bytes_retrans Date: Wed, 20 May 2026 18:21:03 +0200 Message-ID: <20260520162121.067723771@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162111.222830634@linuxfoundation.org> References: <20260520162111.222830634@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit 5efc7b9f7cbd43401f1af81d3d7f2be00f93390d ] tcp_get_timestamping_opt_stats() intentionally runs lockless, we must add READ_ONCE() and WRITE_ONCE() annotations to keep KCSAN happy. Fixes: fb31c9b9f6c8 ("tcp: add data bytes retransmitted stats") Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20260416200319.3608680-9-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/tcp.c | 4 ++-- net/ipv4/tcp_output.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 08678dd21950e..291db82518b03 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -4304,8 +4304,8 @@ struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk, nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, READ_ONCE(tp->bytes_sent), TCP_NLA_PAD); - nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans, - TCP_NLA_PAD); + 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, tp->dsack_dups); nla_put_u32(stats, TCP_NLA_REORD_SEEN, tp->reord_seen); nla_put_u32(stats, TCP_NLA_SRTT, tp->srtt_us >> 3); diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 5d1aa41592720..33c2fb60d0562 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -3414,7 +3414,7 @@ int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs) if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN) __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPSYNRETRANS); WRITE_ONCE(tp->total_retrans, tp->total_retrans + segs); - tp->bytes_retrans += skb->len; + WRITE_ONCE(tp->bytes_retrans, tp->bytes_retrans + skb->len); /* make sure skb->data is aligned on arches that require it * and check if ack-trimming & collapsing extended the headroom -- 2.53.0