From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Holler Subject: Re: [PATCH 1/5] WIP: Add syscall unlinkat_s (currently x86* only) Date: Tue, 03 Feb 2015 09:01:36 +0100 Message-ID: <54D08060.7070504@ahsoftware.de> References: <1422896713-25367-1-git-send-email-holler@ahsoftware.de> <1422896713-25367-2-git-send-email-holler@ahsoftware.de> <20150203060542.GZ29656@ZenIV.linux.org.uk> <54D071AA.1030302@ahsoftware.de> <20150203075616.GA29656@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org To: Al Viro Return-path: In-Reply-To: <20150203075616.GA29656@ZenIV.linux.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org Am 03.02.2015 um 08:56 schrieb Al Viro: > While we are at it, "overwrite with zeroes" is too weak if the attacker > might get hold of the actual hardware. Google for details - it's far too > long story for l-k posting. Look for data recovery and secure data erasure... You might read http://link.springer.com/chapter/10.1007/978-3-540-89862-7_21 Here is an article in german about that: http://www.heise.de/security/meldung/Sicheres-Loeschen-Einmal-ueberschreiben-genuegt-198816.html In short, it's enough to overwrite it once with zeros,