Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751572AbaGTWFM (ORCPT ); Sun, 20 Jul 2014 18:05:12 -0400 Received: from gw1.transmode.se ([195.58.98.146]:57894 "EHLO gw1.transmode.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750882AbaGTWFL (ORCPT ); Sun, 20 Jul 2014 18:05:11 -0400 In-Reply-To: <53CC1FC2.5000806@nod.at> References: <87lhrpayl4.fsf@igel.home> <87fvhwxps6.fsf@igel.home> <87bnskxn7g.fsf@igel.home> <53CBB095.6010705@nod.at> <53CC1FC2.5000806@nod.at> To: Richard Weinberger Cc: LKML , Andreas Schwab MIME-Version: 1.0 Subject: Re: ls -l /proc/1/exe -> Permission denied X-KeepSent: 09FF18A8:BCFCAEF4-C1257D1B:0078E588; type=4; name=$KeepSent X-Mailer: Lotus Notes Release 8.5.3 September 15, 2011 From: Joakim Tjernlund Message-ID: Date: Mon, 21 Jul 2014 00:05:06 +0200 X-MIMETrack: Serialize by Router on mail1/Transmode(Release 8.5.3FP6|November 21, 2013) at 21/07/2014 00:05:06, Serialize complete at 21/07/2014 00:05:06 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Richard Weinberger wrote on 2014/07/20 22:00:02: > > Am 20.07.2014 21:15, schrieb Joakim Tjernlund: > > Richard Weinberger wrote on 2014/07/20 14:05:41: > >> > >> Am 20.07.2014 13:51, schrieb Andreas Schwab: > >>> Richard Weinberger writes: > >>>> Do you have an example? > >>> > >>> proc symlinks are special because they actually resolve to the inode. > >> > >> Ah. If an attacker manages the kernel to follow the symlink he could > >> indirectly access that file. > >> Thanks for pointing this out! > > > > That is a big if, I read this as you don't trust the kernels impl. > > of proc sym links so paper over this with denying all other to read > > trivial > > data such as the exe sym link. > > Feel free to propose a solution for that. :-) I wish I had one :) Good to know why things are how they are though. I guess there is a reason why proc symlinks resolve to the inode? Jocke -- 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/