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=-6.0 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=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 88B79C43381 for ; Mon, 18 Mar 2019 09:34:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5942D21734 for ; Mon, 18 Mar 2019 09:34:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552901668; bh=a11u1miOPobiNlc+9OHlBsKXkFlM3bvsFbfRt/GcvQw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EBdbIcFutFuwIiY+nUwbb7oG5QK3AkdN1SnW50fOxuDSnSHmfcNu6NGNToIp0pLJJ /idb0yZw/C8k1NJvi672gb3S/wbsF8hR+SSSqDY5zqCBOTw9D/owW+fR4mYW4bFyze gBaeNTh2upSYx6CO7nPm+YQc57oG73WajVKXz710= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728729AbfCRJe0 (ORCPT ); Mon, 18 Mar 2019 05:34:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:42816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726973AbfCRJeY (ORCPT ); Mon, 18 Mar 2019 05:34:24 -0400 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 0EC172083D; Mon, 18 Mar 2019 09:34:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552901663; bh=a11u1miOPobiNlc+9OHlBsKXkFlM3bvsFbfRt/GcvQw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Wh70EFC8zUzPpqlzzFyu/ZIbhKGSm9/Z11uujJD2sQNu8lVt8un6Ugsm+7FjwMjCK xlAQINMMlyHZOnVgTT/p5TtBUfVHgnraiNlbN7V0KqmG6cTf10+Ig2UrCXj5JUy7z4 cLQfkVto5meJsTabVXz4+gbDlCyDqiSxWr/s9+OE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiumei Mu , Xin Long , "David S. Miller" Subject: [PATCH 4.14 11/34] pptp: dst_release sk_dst_cache in pptp_sock_destruct Date: Mon, 18 Mar 2019 10:25:35 +0100 Message-Id: <20190318084146.234108525@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190318084144.657740413@linuxfoundation.org> References: <20190318084144.657740413@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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long [ Upstream commit 9417d81f4f8adfe20a12dd1fadf73a618cbd945d ] sk_setup_caps() is called to set sk->sk_dst_cache in pptp_connect, so we have to dst_release(sk->sk_dst_cache) in pptp_sock_destruct, otherwise, the dst refcnt will leak. It can be reproduced by this syz log: r1 = socket$pptp(0x18, 0x1, 0x2) bind$pptp(r1, &(0x7f0000000100)={0x18, 0x2, {0x0, @local}}, 0x1e) connect$pptp(r1, &(0x7f0000000000)={0x18, 0x2, {0x3, @remote}}, 0x1e) Consecutive dmesg warnings will occur: unregister_netdevice: waiting for lo to become free. Usage count = 1 v1->v2: - use rcu_dereference_protected() instead of rcu_dereference_check(), as suggested by Eric. Fixes: 00959ade36ac ("PPTP: PPP over IPv4 (Point-to-Point Tunneling Protocol)") Reported-by: Xiumei Mu Signed-off-by: Xin Long Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ppp/pptp.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/net/ppp/pptp.c +++ b/drivers/net/ppp/pptp.c @@ -539,6 +539,7 @@ static void pptp_sock_destruct(struct so pppox_unbind_sock(sk); } skb_queue_purge(&sk->sk_receive_queue); + dst_release(rcu_dereference_protected(sk->sk_dst_cache, 1)); } static int pptp_create(struct net *net, struct socket *sock, int kern)