Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933074Ab0HLAPj (ORCPT ); Wed, 11 Aug 2010 20:15:39 -0400 Received: from kroah.org ([198.145.64.141]:47842 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933139Ab0HLAI2 (ORCPT ); Wed, 11 Aug 2010 20:08:28 -0400 X-Mailbox-Line: From gregkh@clark.site Wed Aug 11 17:06:15 2010 Message-Id: <20100812000615.730985743@clark.site> User-Agent: quilt/0.48-11.2 Date: Wed, 11 Aug 2010 17:05:48 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Chris Wright , "Serge E. Hallyn" , Al Viro , Christoph Hellwig , "Daniel P. Berrange" Subject: [33/67] blkdev: cgroup whitelist permission fix In-Reply-To: <20100812000641.GA6348@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2032 Lines: 63 2.6.35-stable review patch. If anyone has any objections, please let us know. ------------------ From: Chris Wright commit b7300b78d1a87625975a799a109a2f98d77757c8 upstream. The cgroup device whitelist code gets confused when trying to grant permission to a disk partition that is not currently open. Part of blkdev_open() includes __blkdev_get() on the whole disk. Basically, the only ways to reliably allow a cgroup access to a partition on a block device when using the whitelist are to 1) also give it access to the whole block device or 2) make sure the partition is already open in a different context. The patch avoids the cgroup check for the whole disk case when opening a partition. Addresses https://bugzilla.redhat.com/show_bug.cgi?id=589662 Signed-off-by: Chris Wright Acked-by: Serge E. Hallyn Tested-by: Serge E. Hallyn Reported-by: Vivek Goyal Cc: Al Viro Cc: Christoph Hellwig Cc: "Daniel P. Berrange" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/block_dev.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1339,10 +1339,12 @@ static int __blkdev_get(struct block_dev /* * hooks: /n/, see "layering violations". */ - ret = devcgroup_inode_permission(bdev->bd_inode, perm); - if (ret != 0) { - bdput(bdev); - return ret; + if (!for_part) { + ret = devcgroup_inode_permission(bdev->bd_inode, perm); + if (ret != 0) { + bdput(bdev); + return ret; + } } lock_kernel(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/