linux-kernel - Re: [PATCH v4] ext4: wipe ext4_dir

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Message-ID: <b99d8632-6e3d-b557-0ca4-7416a9d818d5@gmx.com>
Date:   Fri, 2 Jul 2021 13:29:52 +0000
From:   "Artem S. Tashkinov" <aros@....com>
To:     linux-kernel@...r.kernel.org
Cc:     leah.rumancik@...il.com
Subject: Re: [PATCH v4] ext4: wipe ext4_dir_entry2 upon file deletion

Hi,

I'm curious about the nature of this feature. Does it make restoring
accidentally deleted files more difficult or even impossible? OK, data
remains but the patch description makes it sound like all the metadata
is being wiped completely.

 > Upon file deletion, zero out all fields in ext4_dir_entry2
 > besides rec_len. In case sensitive data is stored in filenames,
 > this ensures no potentially sensitive data is left in the directory
 > entry upon deletion. Also, wipe these fields upon moving a directory
 > entry during the conversion to an htree and when splitting htree
 > nodes.

If it's the case, is it possible to make this new security feature user
configurable? I'm OK with it being on by default but I'd be glad if
there were a mount option to disable it.

Best regards,
Artem