From patchwork Tue Nov 27 09:21:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pan Bian X-Patchwork-Id: 10699887 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6B45D13BF for ; Tue, 27 Nov 2018 09:21:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 597202AA75 for ; Tue, 27 Nov 2018 09:21:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4C1E42AA88; Tue, 27 Nov 2018 09:21:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E9C0E2AA75 for ; Tue, 27 Nov 2018 09:21:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730087AbeK0USx (ORCPT ); Tue, 27 Nov 2018 15:18:53 -0500 Received: from m12-15.163.com ([220.181.12.15]:34748 "EHLO m12-15.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729747AbeK0USx (ORCPT ); Tue, 27 Nov 2018 15:18:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id; bh=P7d7oRFMpZRZlDmpOo /WNtGhi4hsYq/yW6a+B3n9tDM=; b=egnCOtzZcjXz52iCk8VBMq08h1scOMjhsb tgX5ggP8iUCetDSdqT28o2zKHTjiNXJiC3xeySCSE0zYaT5O6wot7ep0jgC8IEPy q2sgLLadgRJd2PyP2kTEsvyAvh0AjJsjQn18EtiDhZoL8f2+geagZujILuukSACv thxiqr0dY= Received: from bp.localdomain (unknown [106.120.213.96]) by smtp11 (Coremail) with SMTP id D8CowACHjyyRDP1bJXitAA--.6645S3; Tue, 27 Nov 2018 17:21:24 +0800 (CST) From: Pan Bian To: Ilya Dryomov , "Yan, Zheng" , Sage Weil , "David S. Miller" Cc: ceph-devel@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pan Bian Subject: [PATCH V2] libceph: fix use after free Date: Tue, 27 Nov 2018 17:21:12 +0800 Message-Id: <1543310472-31861-1-git-send-email-bianpan2016@163.com> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: D8CowACHjyyRDP1bJXitAA--.6645S3 X-Coremail-Antispam: 1Uf129KBjvdXoWrKr4DCFy5XFy7XF48tw1UKFg_yoWDArg_Za yUZryvgw1SyFWFk3ZFkws8AF4xWw18uF1fGr1fArW8A34UJrsxArs2v34rZF1xGF4UCw17 XF4Dury5Jr1xZjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU0qXdUUUUUU== X-Originating-IP: [106.120.213.96] X-CM-SenderInfo: held01tdqsiiqw6rljoofrz/xtbBzxQMclaD0boqxAAAs1 Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The function ceph_monc_handle_map calls kfree(old) to free the old monitor map, old points to monc->monmap. However, after that, it reads monc->monmap->epoch and passes it to __ceph_monc_got_map. This will result in a use-after-free bug. The patch moves the free operation after the call to __ceph_monc_got_map. Fixes: 82dcabad750 ("libceph: revamp subs code, switch to SUBSCRIBE2 protocol") Signed-off-by: Pan Bian --- V2: correct the format of the tag Fixes --- net/ceph/mon_client.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c index 18deb3d..05ef5aa 100644 --- a/net/ceph/mon_client.c +++ b/net/ceph/mon_client.c @@ -478,9 +478,10 @@ static void ceph_monc_handle_map(struct ceph_mon_client *monc, } client->monc.monmap = monmap; - kfree(old); __ceph_monc_got_map(monc, CEPH_SUB_MONMAP, monc->monmap->epoch); + kfree(old); + client->have_fsid = true; out: