From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53323 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752371AbcD1AGf (ORCPT ); Wed, 27 Apr 2016 20:06:35 -0400 Subject: Patch "block: partition: initialize percpuref before sending out KOBJ_ADD" has been added to the 4.4-stable tree To: ming.lei@canonical.com, axboe@fb.com, gregkh@linuxfoundation.org, nkaje@codeaurora.org Cc: , From: Date: Wed, 27 Apr 2016 17:06:24 -0700 Message-ID: <146180198493100@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled block: partition: initialize percpuref before sending out KOBJ_ADD to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: block-partition-initialize-percpuref-before-sending-out-kobj_add.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From b30a337ca27c4f40439e4bfb290cba5f88d73bb7 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Wed, 30 Mar 2016 08:46:31 +0800 Subject: block: partition: initialize percpuref before sending out KOBJ_ADD 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 @@ -349,15 +349,20 @@ 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); @@ -366,6 +371,8 @@ 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); Patches currently in stable-queue which might be from ming.lei@canonical.com are queue-4.4/block-partition-initialize-percpuref-before-sending-out-kobj_add.patch queue-4.4/block-loop-fix-filesystem-corruption-in-case-of-aio-dio.patch