From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58364 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752658AbcLLWrH (ORCPT ); Mon, 12 Dec 2016 17:47:07 -0500 Subject: Patch "zram: restrict add/remove attributes to root only" has been added to the 4.4-stable tree To: sergey.senozhatsky@gmail.com, akpm@linux-foundation.org, gregkh@linuxfoundation.org, minchan@kernel.org, steven@stebalien.com, torvalds@linux-foundation.org Cc: , From: Date: Mon, 12 Dec 2016 14:47:12 -0800 Message-ID: <148158283223182@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 zram: restrict add/remove attributes to root only 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: zram-restrict-add-remove-attributes-to-root-only.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 5c7e9ccd91b90d87029261f8856294ee51934cab Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Wed, 7 Dec 2016 14:44:31 -0800 Subject: zram: restrict add/remove attributes to root only From: Sergey Senozhatsky commit 5c7e9ccd91b90d87029261f8856294ee51934cab upstream. zram hot_add sysfs attribute is a very 'special' attribute - reading from it creates a new uninitialized zram device. This file, by a mistake, can be read by a 'normal' user at the moment, while only root must be able to create a new zram device, therefore hot_add attribute must have S_IRUSR mode, not S_IRUGO. [akpm@linux-foundation.org: s/sence/sense/, reflow comment to use 80 cols] Fixes: 6566d1a32bf72 ("zram: add dynamic device add/remove functionality") Link: http://lkml.kernel.org/r/20161205155845.20129-1-sergey.senozhatsky@gmail.com Signed-off-by: Sergey Senozhatsky Reported-by: Steven Allen Acked-by: Greg Kroah-Hartman Cc: Minchan Kim Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/block/zram/zram_drv.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -1378,8 +1378,14 @@ static ssize_t hot_remove_store(struct c return ret ? ret : count; } +/* + * NOTE: hot_add attribute is not the usual read-only sysfs attribute. In a + * sense that reading from this file does alter the state of your system -- it + * creates a new un-initialized zram device and returns back this device's + * device_id (or an error code if it fails to create a new device). + */ static struct class_attribute zram_control_class_attrs[] = { - __ATTR_RO(hot_add), + __ATTR(hot_add, 0400, hot_add_show, NULL), __ATTR_WO(hot_remove), __ATTR_NULL, }; Patches currently in stable-queue which might be from sergey.senozhatsky@gmail.com are queue-4.4/zram-restrict-add-remove-attributes-to-root-only.patch