Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751546AbWEPGrd (ORCPT ); Tue, 16 May 2006 02:47:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751551AbWEPGrd (ORCPT ); Tue, 16 May 2006 02:47:33 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:17837 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S1751544AbWEPGrc (ORCPT ); Tue, 16 May 2006 02:47:32 -0400 Date: Tue, 16 May 2006 08:47:23 +0200 From: Ingo Molnar To: Rusty Russell Cc: lkml - Kernel Mailing List , Linus Torvalds , virtualization , Gerd Hoffmann , Zachary Amsden Subject: Re: [PATCH] Gerd Hoffman's move-vsyscall-into-user-address-range patch Message-ID: <20060516064723.GA14121@elte.hu> References: <1147759423.5492.102.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1147759423.5492.102.camel@localhost.localdomain> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: -2.8 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.8 required=5.9 tests=ALL_TRUSTED,AWL autolearn=no SpamAssassin version=3.0.3 -2.8 ALL_TRUSTED Did not pass through any untrusted hosts 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 966 Lines: 21 * Rusty Russell wrote: > AFAICT we'll pay one extra TLB entry for this patch. Zach had a patch > which left the vsyscall page at the top of memory (minus hole for > hypervisor) and patched the ELF header at boot. i'd suggest the solution from exec-shield (which has been there for a long time), which also randomizes the vsyscall vma. Exploits are already starting to use the vsyscall page (with predictable addresses) to circumvent randomization, it provides 'interesting' instructions to act as a syscall-functionality building block. Moving that address to another predictable place solves the virtualization problem, but doesnt solve the address-space randomization problem. Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/