From patchwork Tue Apr 10 21:19:39 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Jiang X-Patchwork-Id: 10333857 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 73BAF6053B for ; Tue, 10 Apr 2018 21:19:43 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 558E22223E for ; Tue, 10 Apr 2018 21:19:43 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 47D3A28403; Tue, 10 Apr 2018 21:19:43 +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=-2.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id AFD6C2223E for ; Tue, 10 Apr 2018 21:19:42 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id E9AD222618161; Tue, 10 Apr 2018 14:19:41 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=134.134.136.31; helo=mga06.intel.com; envelope-from=dave.jiang@intel.com; receiver=linux-nvdimm@lists.01.org Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 2668D2261815B for ; Tue, 10 Apr 2018 14:19:40 -0700 (PDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Apr 2018 14:19:40 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,433,1517904000"; d="scan'208";a="45856250" Received: from djiang5-desk3.ch.intel.com ([143.182.136.93]) by fmsmga001.fm.intel.com with ESMTP; 10 Apr 2018 14:19:39 -0700 Subject: [PATCH v2] libnvdimm: fix NULL ptr access in nvdimm_flush when region is disabled From: Dave Jiang To: dan.j.williams@intel.com Date: Tue, 10 Apr 2018 14:19:39 -0700 Message-ID: <152339515127.30466.8052576975908716815.stgit@djiang5-desk3.ch.intel.com> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-nvdimm@lists.01.org Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP When a region is disabled, there is no driver attached. Therefore dev->driverdata is NULL. An attempt to write to regionN/deep_flush via sysfs would cause a NULL pointer dereference. Bail when dev->driver is NULL to protect this scenario. Fix: ab630891ce0eb(libnvdimm, region: sysfs trigger for nvdimm_flush()) Signed-off-by: Dave Jiang --- v2: Move to deep_flush_store. (Dan) drivers/nvdimm/region_devs.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index a612be6f019d..65cc2a5b48b8 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -290,6 +290,11 @@ static ssize_t deep_flush_store(struct device *dev, struct device_attribute *att return rc; if (!flush) return -EINVAL; + + /* protect against disabled region */ + if (!nd_region->dev.driver) + return -ENXIO; + nvdimm_flush(nd_region); return len;