From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754392Ab2HNMfm (ORCPT ); Tue, 14 Aug 2012 08:35:42 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:45363 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752486Ab2HNMfl (ORCPT ); Tue, 14 Aug 2012 08:35:41 -0400 Date: Tue, 14 Aug 2012 13:40:20 +0100 From: Alan Cox To: Ajay Garg Cc: linux-kernel@vger.kernel.org Subject: Re: How to hack syscall-table, in kernel 2.6+ ? Message-ID: <20120814134020.367361b5@pyramind.ukuu.org.uk> In-Reply-To: References: X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > I have already tried extracting the address of the "sys_call_table" > from "System.Map"; however, I am still not able to replace the > function-pointers with mine. Correct. > Trying to do gives me page-faults, apparently meaning that the > syscall-table memory area is read-only. Correct. The kernel is specifically designed to stop such uses by rootkits and trojans and other malware. If you are trying to patch the system call table you are doing something wrong. What are you actually trying to achieve ?