From patchwork Tue Mar 3 17:41:16 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 230062 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, 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 B12DAC3F2D1 for ; Tue, 3 Mar 2020 17:44:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8C54D20CC7 for ; Tue, 3 Mar 2020 17:44:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583257480; bh=RBkE2p+p1wkYJ94iTvM47rJcXwsX+MC8/AcJdXC+qCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JG8jPDzX1gZCKz1csmmNSP8Pmwo1DqHowb0uXDn+Gv1iLv9vJKKsjyCoPi3hXnhuV S36bb8oEikozAw0gwjkcxpuK9S4qNmrSxkrGgW5YwlWlFwfCUG/nh+w+OaXJEMGbcH BqN+RQUnTYjlpB4YfMGz2e9jVkg15GVJAvbUDKSI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730160AbgCCRoj (ORCPT ); Tue, 3 Mar 2020 12:44:39 -0500 Received: from mail.kernel.org ([198.145.29.99]:50270 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729311AbgCCRoj (ORCPT ); Tue, 3 Mar 2020 12:44:39 -0500 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 1B554208C3; Tue, 3 Mar 2020 17:44:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583257478; bh=RBkE2p+p1wkYJ94iTvM47rJcXwsX+MC8/AcJdXC+qCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cmtR6spT7wy33dVIHtBfLEb70xNSMpa4OxOAhp/54VR1kYByaURuqGJkhviqTL3HE Mw9PrRiw/agVM7c92qI0H7Q5fHllM6LDb/EWdv/TsCmW4YB3HRXsBAe6Mn3LjRjSmW kYLd4gtQGadS214XCTAdbcaeeQrLAk3v6MtLAZcg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Roskin , Willem de Bruijn , Eric Dumazet , "David S. Miller" Subject: [PATCH 5.5 012/176] udp: rehash on disconnect Date: Tue, 3 Mar 2020 18:41:16 +0100 Message-Id: <20200303174305.990010916@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200303174304.593872177@linuxfoundation.org> References: <20200303174304.593872177@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Willem de Bruijn [ Upstream commit 303d0403b8c25e994e4a6e45389e173cf8706fb5 ] As of the below commit, udp sockets bound to a specific address can coexist with one bound to the any addr for the same port. The commit also phased out the use of socket hashing based only on port (hslot), in favor of always hashing on {addr, port} (hslot2). The change broke the following behavior with disconnect (AF_UNSPEC): server binds to 0.0.0.0:1337 server connects to 127.0.0.1:80 server disconnects client connects to 127.0.0.1:1337 client sends "hello" server reads "hello" // times out, packet did not find sk On connect the server acquires a specific source addr suitable for routing to its destination. On disconnect it reverts to the any addr. The connect call triggers a rehash to a different hslot2. On disconnect, add the same to return to the original hslot2. Skip this step if the socket is going to be unhashed completely. Fixes: 4cdeeee9252a ("net: udp: prefer listeners bound to an address") Reported-by: Pavel Roskin Signed-off-by: Willem de Bruijn Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/udp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1856,8 +1856,12 @@ int __udp_disconnect(struct sock *sk, in inet->inet_dport = 0; sock_rps_reset_rxhash(sk); sk->sk_bound_dev_if = 0; - if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) { inet_reset_saddr(sk); + if (sk->sk_prot->rehash && + (sk->sk_userlocks & SOCK_BINDPORT_LOCK)) + sk->sk_prot->rehash(sk); + } if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) { sk->sk_prot->unhash(sk);