From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B4403C433E1 for ; Tue, 23 Jun 2020 21:42:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 79DEF2078A for ; Tue, 23 Jun 2020 21:42:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592948524; bh=jYH2ofygeD+0zmgRGpm0zRKztlE5jlZuot/MKcHt1YY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=L+q5zErTPz/79+UQgH/vzaDaQuIfkZS0xGH2EK9kdoQ6vzJbrw3YdjnvVpgnku0Wr OLgGQDC47brYX0O2olo4OLPgpOOg/d1rNcLeWsxOR4T0p9j06iEnsxDESn+xf/KsNN Epv21eMegUXT2Uts66JJIWpQa54J2F9qzxVcgOdQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388840AbgFWVmC (ORCPT ); Tue, 23 Jun 2020 17:42:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:44718 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388329AbgFWUFV (ORCPT ); Tue, 23 Jun 2020 16:05:21 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D10DF2078A; Tue, 23 Jun 2020 20:05:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592942721; bh=jYH2ofygeD+0zmgRGpm0zRKztlE5jlZuot/MKcHt1YY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t/CcdlIn4dDIkMXlFKfLkFG299ILJrbxa2nK97bJQ7HBJupPaEaSj15TWU5OU3zkA MMkMWk9P2NWCbsVX2Gs/tqwPiqj8ou2Gn1H8gks36nHv7ZBI6MFpEVLFNzNaa2rFbX 5hfjUW4XAsC+ryxLY4SZsndZalgQ4fyGADPDUKic= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sabrina Dubroca , Alexei Starovoitov , Jakub Sitnicki , Sasha Levin Subject: [PATCH 5.7 110/477] bpf: tcp: Recv() should return 0 when the peer socket is closed Date: Tue, 23 Jun 2020 21:51:47 +0200 Message-Id: <20200623195412.789436573@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200623195407.572062007@linuxfoundation.org> References: <20200623195407.572062007@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sabrina Dubroca [ Upstream commit 2c7269b231194aae23fb90ab65842573a91acbc9 ] If the peer is closed, we will never get more data, so tcp_bpf_wait_data will get stuck forever. In case we passed MSG_DONTWAIT to recv(), we get EAGAIN but we should actually get 0. >>From man 2 recv: RETURN VALUE When a stream socket peer has performed an orderly shutdown, the return value will be 0 (the traditional "end-of-file" return). This patch makes tcp_bpf_wait_data always return 1 when the peer socket has been shutdown. Either we have data available, and it would have returned 1 anyway, or there isn't, in which case we'll call tcp_recvmsg which does the right thing in this situation. Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface") Signed-off-by: Sabrina Dubroca Signed-off-by: Alexei Starovoitov Acked-by: Jakub Sitnicki Link: https://lore.kernel.org/bpf/26038a28c21fea5d04d4bd4744c5686d3f2e5504.1591784177.git.sd@queasysnail.net Signed-off-by: Sasha Levin --- net/ipv4/tcp_bpf.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 629aaa9a1eb99..9c5540887fbe5 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -242,6 +242,9 @@ static int tcp_bpf_wait_data(struct sock *sk, struct sk_psock *psock, DEFINE_WAIT_FUNC(wait, woken_wake_function); int ret = 0; + if (sk->sk_shutdown & RCV_SHUTDOWN) + return 1; + if (!timeo) return ret; -- 2.25.1