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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 D586BC7112A for ; Sun, 14 Oct 2018 16:03:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99D7A20645 for ; Sun, 14 Oct 2018 16:03:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 99D7A20645 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727469AbeJNXor (ORCPT ); Sun, 14 Oct 2018 19:44:47 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35732 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727152AbeJNXLp (ORCPT ); Sun, 14 Oct 2018 19:11:45 -0400 Received: from [2a02:8011:400e:2:cbab:f00:c93f:614] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1gBiLY-0004cZ-QQ; Sun, 14 Oct 2018 16:30:25 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gBiLV-0000TG-R9; Sun, 14 Oct 2018 16:30:21 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Ilya Dryomov" , "Jason Dillaman" Date: Sun, 14 Oct 2018 16:25:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 229/366] libceph: validate con->state at the top of try_write() In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:cbab:f00:c93f:614 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.60-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Ilya Dryomov commit 9c55ad1c214d9f8c4594ac2c3fa392c1c32431a7 upstream. ceph_con_workfn() validates con->state before calling try_read() and then try_write(). However, try_read() temporarily releases con->mutex, notably in process_message() and ceph_con_in_msg_alloc(), opening the window for ceph_con_close() to sneak in, close the connection and release con->sock. When try_write() is called on the assumption that con->state is still valid (i.e. not STANDBY or CLOSED), a NULL sock gets passed to the networking stack: BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 IP: selinux_socket_sendmsg+0x5/0x20 Make sure con->state is valid at the top of try_write() and add an explicit BUG_ON for this, similar to try_read(). Link: https://tracker.ceph.com/issues/23706 Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman Signed-off-by: Ben Hutchings --- net/ceph/messenger.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -2453,6 +2453,11 @@ static int try_write(struct ceph_connect int ret = 1; dout("try_write start %p state %lu\n", con, con->state); + if (con->state != CON_STATE_PREOPEN && + con->state != CON_STATE_CONNECTING && + con->state != CON_STATE_NEGOTIATING && + con->state != CON_STATE_OPEN) + return 0; more: dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes); @@ -2478,6 +2483,8 @@ more: } more_kvec: + BUG_ON(!con->sock); + /* kvec data queued? */ if (con->out_skip) { ret = write_partial_skip(con);