From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934271AbcECBZt (ORCPT ); Mon, 2 May 2016 21:25:49 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60609 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932406AbcECAeB (ORCPT ); Mon, 2 May 2016 20:34:01 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Naveen Kaje , Ming Lei , Jens Axboe Subject: [PATCH 4.5 002/200] block: partition: initialize percpuref before sending out KOBJ_ADD Date: Mon, 2 May 2016 17:10:01 -0700 Message-Id: <20160503000554.711396048@linuxfoundation.org> X-Mailer: git-send-email 2.8.2 In-Reply-To: <20160503000554.631204776@linuxfoundation.org> References: <20160503000554.631204776@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ming Lei commit b30a337ca27c4f40439e4bfb290cba5f88d73bb7 upstream. The initialization of partition's percpu_ref should have been done before sending out KOBJ_ADD uevent, which may cause userspace to read partition table. So the uninitialized percpu_ref may be accessed in data path. This patch fixes this issue reported by Naveen. Reported-by: Naveen Kaje Tested-by: Naveen Kaje Fixes: 6c71013ecb7e2(block: partition: convert percpu ref) Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- block/partition-generic.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -350,15 +350,20 @@ struct hd_struct *add_partition(struct g goto out_del; } + err = hd_ref_init(p); + if (err) { + if (flags & ADDPART_FLAG_WHOLEDISK) + goto out_remove_file; + goto out_del; + } + /* everything is up and running, commence */ rcu_assign_pointer(ptbl->part[partno], p); /* suppress uevent if the disk suppresses it */ if (!dev_get_uevent_suppress(ddev)) kobject_uevent(&pdev->kobj, KOBJ_ADD); - - if (!hd_ref_init(p)) - return p; + return p; out_free_info: free_part_info(p); @@ -367,6 +372,8 @@ out_free_stats: out_free: kfree(p); return ERR_PTR(err); +out_remove_file: + device_remove_file(pdev, &dev_attr_whole_disk); out_del: kobject_put(p->holder_dir); device_del(pdev);