Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756056Ab1F1BRS (ORCPT ); Mon, 27 Jun 2011 21:17:18 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:56451 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755761Ab1F1BPW convert rfc822-to-8bit (ORCPT ); Mon, 27 Jun 2011 21:15:22 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=LH8FLl/5r+RlveTwpcOdDXFgS5fAsosPFE7BroCOKuBGVYW8/KpcvR8hSJpssQeWxR a2v/177wBwTbOi49gie+o1cnjot9dTGWHFgccrKLOMN7CCW//k4Ik9HS2QsXfIJiU8o2 G55NK4r4gyop69fKDEPBjg6HKxGw+K4yE6aDI= MIME-Version: 1.0 In-Reply-To: References: <1308917318-4749-1-git-send-email-segoon@openwall.com> Date: Tue, 28 Jun 2011 06:45:21 +0530 Message-ID: Subject: Re: [PATCH 1/2] proc: restrict access to /proc/PID/io From: Balbir Singh To: Vasiliy Kulikov Cc: linux-kernel@vger.kernel.org, Andrew Morton , Al Viro , David Rientjes , Stephen Wilson , KOSAKI Motohiro , security@kernel.org, Eric Paris , Solar Designer Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1105 Lines: 25 On Tue, Jun 28, 2011 at 6:43 AM, Balbir Singh wrote: > On Fri, Jun 24, 2011 at 5:38 PM, Vasiliy Kulikov wrote: >> /proc/PID/io may be used for gathering private information. ?E.g. for >> openssh and vsftpd daemons wchars/rchars may be used to learn the >> precise password length. ?Restrict it to processes being able to ptrace >> the target process. >> > > Hmm.. How do I reproduce this, won't they be enough randomness around > rchar/wchar by the time the attacker reads it? > >> ptrace_may_access() is needed to prevent keeping open file descriptor of >> "io" file, executing setuid binary and gathering io information of the >> setuid'ed process. Please NOTE my email address has changed to bsingharora@gmail.com, the last email has an invalid from header. I apologize for the inconvenience Balbir Singh -- 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/