From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 9CFBD17756 for ; Wed, 9 Aug 2023 11:20:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E481C433C8; Wed, 9 Aug 2023 11:20:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691580055; bh=q4Z7s2QYT6XHIW8+sih7dykltDnnCwI5m4UK0TfmINQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iUG0K3+wlvhOeYFUPrIJA/lsVROku1MCCYUA+3Km7977APfW0fpG/HSm9u2hwbuTN 2IwW8M8cH3RkgWKihPMtVxhSB+GOmPix0sMaNytcH1LA4WZEJw0yLlaD46C80bslqy OoevAlA8LKs32oDd+Zc5MivUzWqlN0Taq4wwhxvE= 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 4.19 212/323] tcp: annotate data-races around tp->linger2 Date: Wed, 9 Aug 2023 12:40:50 +0200 Message-ID: <20230809103707.832332000@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103658.104386911@linuxfoundation.org> References: <20230809103658.104386911@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Eric Dumazet [ Upstream commit 9df5335ca974e688389c875546e5819778a80d59 ] do_tcp_getsockopt() reads tp->linger2 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/20230719212857.3943972-8-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv4/tcp.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 9f3cdcbbb7590..4711963413a49 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3000,11 +3000,11 @@ static int do_tcp_setsockopt(struct sock *sk, int level, case TCP_LINGER2: if (val < 0) - tp->linger2 = -1; + WRITE_ONCE(tp->linger2, -1); else if (val > TCP_FIN_TIMEOUT_MAX / HZ) - tp->linger2 = TCP_FIN_TIMEOUT_MAX; + WRITE_ONCE(tp->linger2, TCP_FIN_TIMEOUT_MAX); else - tp->linger2 = val * HZ; + WRITE_ONCE(tp->linger2, val * HZ); break; case TCP_DEFER_ACCEPT: @@ -3401,7 +3401,7 @@ static int do_tcp_getsockopt(struct sock *sk, int level, val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries; break; case TCP_LINGER2: - val = tp->linger2; + val = READ_ONCE(tp->linger2); if (val >= 0) val = (val ? : READ_ONCE(net->ipv4.sysctl_tcp_fin_timeout)) / HZ; break; -- 2.39.2