From owner-freebsd-arch@FreeBSD.ORG Wed May 20 16:32:03 2015 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 327D924B for ; Wed, 20 May 2015 16:32:03 +0000 (UTC) Received: from mail-ie0-f180.google.com (mail-ie0-f180.google.com [209.85.223.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 044311113 for ; Wed, 20 May 2015 16:32:02 +0000 (UTC) Received: by iebgx4 with SMTP id gx4so43336108ieb.0 for ; Wed, 20 May 2015 09:31:56 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=IiTwmtD7a0LZIKBLgisp6hzuosL5Ypw7HU7rCBvG2TU=; b=dBa8VxRPpcs1JapL+vh83dottoqMUze0+B5QFrAWBJyncEs/2V1LalJxMNHPodla4i 1Ff+mnYT182Okv1wP6ntkJ+6f6u7hWYlEdldQJN9JM0XkKJubiZd3pB7WFB3ZlySpDM7 37tkb+Ztnz824UPiIG7j5Z+qUcod52EhY0mnHu4gEv9sQVyjgm2k7gyjwFsvsVTPTIV4 0qzX+e7SzyJU1m8gYWflYUxY9Q4Axt10wbTq2Fu5LpnxYHeRKzCyTv7ipyj0JR2RgmOT 4a++hEJiOmxkBJpaJL2n1ZUbk94BrHji9Z95CM0t18mpoCKNdsyjHYJlFA5GGa/9jpWb LoMw== X-Gm-Message-State: ALoCoQmGxo9FXy8Q4Q58rS9w1EyIFE8LujYewFNrLETknxhzbJn02ix5yS5M0Ic2DgQDhKHS/m8L MIME-Version: 1.0 X-Received: by 10.43.173.70 with SMTP id ob6mr46563159icc.45.1432139516323; Wed, 20 May 2015 09:31:56 -0700 (PDT) Received: by 10.79.11.6 with HTTP; Wed, 20 May 2015 09:31:56 -0700 (PDT) In-Reply-To: <555CADB6.202@FreeBSD.org> References: <555CADB6.202@FreeBSD.org> Date: Wed, 20 May 2015 18:31:56 +0200 Message-ID: Subject: Re: ASLR work into -HEAD ? From: Oliver Pinter To: Pedro Giffuni Cc: Shawn Webb , "freebsd-arch@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 May 2015 16:32:03 -0000 On 5/20/15, Pedro Giffuni wrote: > Hello Shawn; > > What ever happened to the performance, does it still have a > noticeable effect even when disabled? We should ask to run an exp-run again with/without/disabled ASLR. > > I have no technical opinion on the patch, but ... > > TBH, the problem I see is that ASLR is so widespread that every > potential attacker already knows how to defeat it. Yes, it is meant > only as a mitigation technique but if it only buys you 5 min. > (at most) I don't see much advantage in obfuscating the VM. Hi Pedro! Explain the situation, when someone release an exploit against one system without ASLR. The attacker hard code the address of the specific code, and try it against the whole internet. In this case all of the try will success. Then explain the other situation, when the system has ASLR. In this case the exploit in the majority fails, and the attacker must to try multiple times to attack the system. This is very large cost on their side... Sometimes this 5 minutes means that the attacker could break in or not. Most of the average attackers does not have the knowledge, how to bypass the ASLR. Yes, there exists automated ROP generator and other tools, and articles about blink ROP effectiveness, but in the real life the ASLR is a must have. The ASLR would much more efficient, when segvguard or similar brute force prevention solution existing in the system. > > Just IMHO ... I am not a player in that area and I don't maintain > the underlying code so I don't approve or reject anything. > > Pedro. > _______________________________________________ > freebsd-arch@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-arch > To unsubscribe, send any mail to "freebsd-arch-unsubscribe@freebsd.org" >