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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 C4B48C2F3A0 for ; Mon, 21 Jan 2019 14:21:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8BB1920861 for ; Mon, 21 Jan 2019 14:21:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548080473; bh=PUPjDHkMRwFFZcDn4vmCV/eZlDSo/+LL/PlRRpew5Co=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NjB0XvbQJxGPA6iWn+GH206OFV9+63IYFN3TkFAGgDhoSmvWbMmhHr6wNkLJ5NJHG D2PiTpbFbN4dUFxqklenBFiqWEZRU7LlIrpgRzbYKZqlQjW9TpA0090QHbxcEL4ajE i8XO+HHrYvYwdusxNbfV9DLClYFBg9tP/LspRydM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729824AbfAUOVG (ORCPT ); Mon, 21 Jan 2019 09:21:06 -0500 Received: from mail.kernel.org ([198.145.29.99]:56560 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729556AbfAUNrS (ORCPT ); Mon, 21 Jan 2019 08:47:18 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.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 59E1720861; Mon, 21 Jan 2019 13:47:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548078437; bh=PUPjDHkMRwFFZcDn4vmCV/eZlDSo/+LL/PlRRpew5Co=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OCgANgcnaBy0YFGtiKOq6/RzSErtuVUWP9LlTLds1DLFbLhPYyv3iioV4PUwRHY/X acN8ys0eG1FgJXoqaieVey1IgBCtJqlNdt129WHmUjKQPHhsm9dafjG9EDIg13i8RI FW52xtJOgscjGGo8n1ylC3T0C+ya5p3x18eJ+hdE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ursula Braun , Cong Wang , syzbot+0bf2e01269f1274b4b03@syzkaller.appspotmail.com, syzbot+e3132895630f957306bc@syzkaller.appspotmail.com, "David S. Miller" , syzbot+fbd1e5476e4c94c7b34e@syzkaller.appspotmail.com Subject: [PATCH 4.20 031/111] smc: move unhash as early as possible in smc_release() Date: Mon, 21 Jan 2019 14:42:25 +0100 Message-Id: <20190121122459.261048518@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190121122455.819406896@linuxfoundation.org> References: <20190121122455.819406896@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore 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 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cong Wang [ Upstream commit 26d92e951fe0a44ee4aec157cabb65a818cc8151 ] In smc_release() we release smc->clcsock before unhash the smc sock, but a parallel smc_diag_dump() may be still reading smc->clcsock, therefore this could cause a use-after-free as reported by syzbot. Reported-and-tested-by: syzbot+fbd1e5476e4c94c7b34e@syzkaller.appspotmail.com Fixes: 51f1de79ad8e ("net/smc: replace sock_put worker by socket refcounting") Cc: Ursula Braun Signed-off-by: Cong Wang Reported-by: syzbot+0bf2e01269f1274b4b03@syzkaller.appspotmail.com Reported-by: syzbot+e3132895630f957306bc@syzkaller.appspotmail.com Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/smc/af_smc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -146,6 +146,9 @@ static int smc_release(struct socket *so sock_set_flag(sk, SOCK_DEAD); sk->sk_shutdown |= SHUTDOWN_MASK; } + + sk->sk_prot->unhash(sk); + if (smc->clcsock) { if (smc->use_fallback && sk->sk_state == SMC_LISTEN) { /* wake up clcsock accept */ @@ -170,7 +173,6 @@ static int smc_release(struct socket *so smc_conn_free(&smc->conn); release_sock(sk); - sk->sk_prot->unhash(sk); sock_put(sk); /* final sock_put */ out: return rc;