linux-ext4 - Re: mounting ext3 with another superblock doesn't work?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20110509132818.GI4138@thunk.org>
Date:	Mon, 9 May 2011 09:28:18 -0400
From:	Ted Ts'o <tytso@....edu>
To:	Jan Kara <jack@...e.cz>
Cc:	Christoph Anton Mitterer <calestyo@...entia.net>,
	linux-fsdevel@...r.kernel.org, linux-ext4@...r.kernel.org,
	adilger@...ger.ca, amir73il@...rs.sourceforge.net
Subject: Re: mounting ext3 with another superblock doesn't work?

On Mon, May 09, 2011 at 02:06:08PM +0200, Jan Kara wrote:
>   Yes, that would be reasonable although it might break some people's
> scripts. But probably worth it anyway.

I wouldn't object to a patch to e2fsprogs which changes mke2fs to do
this check and refuses to blow away a file system if:

[defaults]
    check_for_prexisting_fs = true

was in /etc/mke2fs.conf.

I'd also suggest that mke2fs -f NOT enable mke2fs to blow away file
systems, but that we add a new utility --- probably to util-linux-ng
--- with the destroy_partition, which a system administrator has to
explicitly run to blow away a partition.

I'd really rather not train people that mke2fs -f is the way to get
the utility to !@#@! shut up.  It's exactly the same problem with why
"alias rm 'rm -i'" doesn't work.  System administrators just get in
the habit of typing return, 'y', return, and in the end things still
just get lost.

If we have a separate utility, destroy_filesystem, which checks to see
if there is a tty, and if so, prints the details of what is on the
partition, and then forces the user to type "YES<return>", then we
have a unified way of protecting against careless sysadmins.  We can
also have that utility do clever things, such as simply telling the
hard drive to reinitiailize its crypto keys if it supports FDE, or
tell it to TRIM the entire disk if it supports TRIM/DISCARD, etc.

							- Ted
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html