From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zheng Liu Subject: Re: [PATCH 2/2] ext4: avoid hang when mounting non-journal filesystems with orphan list Date: Thu, 27 Dec 2012 15:19:14 +0800 Message-ID: <20121227071914.GB7573@gmail.com> References: <1356590595-23144-1-git-send-email-tytso@mit.edu> <1356590595-23144-2-git-send-email-tytso@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Ext4 Developers List , stable@vger.kernel.org To: Theodore Ts'o Return-path: Content-Disposition: inline In-Reply-To: <1356590595-23144-2-git-send-email-tytso@mit.edu> Sender: stable-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Thu, Dec 27, 2012 at 01:43:15AM -0500, Theodore Ts'o wrote: > When trying to mount a file system which does not contain a journal, > but which does have a orphan list with an inode which needs to be > truncated, the mount call with hang forever in ext4_orphan_cleanup() > because ext4_orphan_del() will return immediately if no journal is > present. > > This can be trivially reproduced by trying to mount the file system > found in tests/f_orphan_extents_inode/image.gz in the e2fsprogs > sources. If a malicious user were to put this on a USB stick, and > mount it on a Linux desktop which automatically mounts newly inserted > USB sticks, this could be considered a potential denial of service > attack. (Not a big deal in practice, but professional paranoids worry > about such things, and have even been known to allocate CVE numbers > on occasion.) > > Signed-off-by: "Theodore Ts'o" > Cc: stable@vger.kernel.org Reviewed-by: Zheng Liu Regards, - Zheng