Received: by 2002:a05:6a10:1287:0:0:0:0 with SMTP id d7csp687996pxv; Thu, 22 Jul 2021 09:45:12 -0700 (PDT) X-Google-Smtp-Source: ABdhPJwl5UeGmmcTbPHs8vjoP/kb7l0uUY5qse52curprQHRIKUMXC+0TD5p+FDt5vvEwym0S9L7 X-Received: by 2002:a05:6638:1350:: with SMTP id u16mr393213jad.19.1626972312206; Thu, 22 Jul 2021 09:45:12 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1626972312; cv=none; d=google.com; s=arc-20160816; b=LWf7brU3liDV5KhskaHjE/gxKFpjDT7FbxMq9b/8cVb+ys/ljzalY+WtJ9yPeKJQe0 v9xOaxEWJiiW1jV4Zj36RwCeqXiRZV/9o/dA5bUiot21NwfHN72iMTZPS++G8AUaOsCW rSZFat6PjCY30+HdrK98dhQ9FZoqvQ+Gr08lJgCZQIc9LUsffg9ZUwnQ9V8C4XNvw23U Vx7hdzcHhctifKahEUfpQdaCHcaPAW8HOewHS7Ntyui4rfmB1ZqlRT61WeJr8OLlYmrT UqovuC0z76HfzUIpHRWH5a3Q+7Mfu8YuEZkx91sddb5C7jKDKk3zY/r4foA/w8vU1rb3 of9Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:message-id:date:subject:cc:to :from:dkim-signature; bh=9m4/1tK5BEQnFQ/rkEknH8nLzZSuYb+T1c1k/8SMSpM=; b=EOp4tjJHWDPpsigoL30PnGM5o18LJ3Ty4wecWrxVIUD9JdkWTYQcD3TI1qSxfLYxNs GY87vp3+P68u6TY6xVBTrBjoe+EJOBf0ApkanHZiQez+CbahWWcisBp3E+WABb6vfiQI AaNZYQlXfhITsilzhv1vvtwtCzBpLoegXjUWkdeEo2z6yqanBBkCAOFsWcmnnsSBGVel TLsa84F2MDldK5X0aU3OEiuPLGHuEJXB4EGUgH9gIV2mkg/WjicXBGaCxL40MU2cTQGi bvZtqzBDeh6XmqQqJ45v+i/O1/h7TM8SldNAzgDi2o6wGjPtxY1lbSue9aMPk0Z6dhMg s5Sw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b="btT/it+l"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id ay38si30953261jab.21.2021.07.22.09.45.00; Thu, 22 Jul 2021 09:45:12 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b="btT/it+l"; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233099AbhGVQDZ (ORCPT + 99 others); Thu, 22 Jul 2021 12:03:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:39144 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233670AbhGVQBu (ORCPT ); Thu, 22 Jul 2021 12:01:50 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 014E5613D4; Thu, 22 Jul 2021 16:42:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626972144; bh=ThXlEs92FBXVCti8cyyCvp0sAcHbzL4TpZlBG5kLZms=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=btT/it+lYHsKUdZPdre/cj4wLUC0oVKr4NoTX08Lk4byCw+Hxq7sOgvF2LJceqim3 G6vGkryrDn15x+mzJwL7+ZdaRIX1J7EiVTSH31fTmWzR+6JRIYZV8H7DxzVV7iopIz K5o5rZamdvYz8J3j0bDFEeOknlrwJTGOMR6qgRec= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eric Dumazet , "David S. Miller" Subject: [PATCH 5.10 116/125] tcp: annotate data races around tp->mtu_info Date: Thu, 22 Jul 2021 18:31:47 +0200 Message-Id: <20210722155628.558932262@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210722155624.672583740@linuxfoundation.org> References: <20210722155624.672583740@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric Dumazet commit 561022acb1ce62e50f7a8258687a21b84282a4cb upstream. While tp->mtu_info is read while socket is owned, the write sides happen from err handlers (tcp_v[46]_mtu_reduced) which only own the socket spinlock. Fixes: 563d34d05786 ("tcp: dont drop MTU reduction indications") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/tcp_ipv4.c | 4 ++-- net/ipv6/tcp_ipv6.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -342,7 +342,7 @@ void tcp_v4_mtu_reduced(struct sock *sk) if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) return; - mtu = tcp_sk(sk)->mtu_info; + mtu = READ_ONCE(tcp_sk(sk)->mtu_info); dst = inet_csk_update_pmtu(sk, mtu); if (!dst) return; @@ -546,7 +546,7 @@ int tcp_v4_err(struct sk_buff *skb, u32 if (sk->sk_state == TCP_LISTEN) goto out; - tp->mtu_info = info; + WRITE_ONCE(tp->mtu_info, info); if (!sock_owned_by_user(sk)) { tcp_v4_mtu_reduced(sk); } else { --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -352,7 +352,7 @@ static void tcp_v6_mtu_reduced(struct so if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) return; - dst = inet6_csk_update_pmtu(sk, tcp_sk(sk)->mtu_info); + dst = inet6_csk_update_pmtu(sk, READ_ONCE(tcp_sk(sk)->mtu_info)); if (!dst) return; @@ -443,7 +443,7 @@ static int tcp_v6_err(struct sk_buff *sk if (!ip6_sk_accept_pmtu(sk)) goto out; - tp->mtu_info = ntohl(info); + WRITE_ONCE(tp->mtu_info, ntohl(info)); if (!sock_owned_by_user(sk)) tcp_v6_mtu_reduced(sk); else if (!test_and_set_bit(TCP_MTU_REDUCED_DEFERRED,