From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 9 Aug 2001 06:23:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 9 Aug 2001 06:22:51 -0400 Received: from web13606.mail.yahoo.com ([216.136.175.117]:3589 "HELO web13606.mail.yahoo.com") by vger.kernel.org with SMTP id ; Thu, 9 Aug 2001 06:22:32 -0400 Message-ID: <20010809102243.95913.qmail@web13606.mail.yahoo.com> Date: Thu, 9 Aug 2001 03:22:43 -0700 (PDT) From: Ivan Kalvatchev Subject: DoS with tmpfs #dynamic To: kernelbug In-Reply-To: <3B722DE4.96DA5711@idb.hist.no> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --- Helge Hafting wrote: > The problem with this is that tmpfs may be mounted > before > swap is initialized, so a little less than > swap+ram will become "a little less than just RAM" > anyway. > > Or do you propose a dynamic limit, changing as swap > is added/removed? This has problems if some swap is > removed, and suddenly tmpfs usage exceeds its quota. > > Helge Hafting Yes I mean it. If tmpfs is fixed in any way the problem will raise. If it is dynamic we have 2 possible ways: 1. First we fill most of tmpfs. Then we start some program that needs a tones of ram. The program exit with error and System is stable. 2. We use a lot of memory. The tmpfs decreases it's size dynamicly and then when trying to fill it up it return No space on device. About swap removing. What gonna happen if ram and swap are full and someone tries to remove the swap. Data loss? P.S. Pleace don't forget that ramfs is vulnarable in the same way. It is rarely used but is DANGEROUS. Ivan Kalvachev __________________________________________________ Do You Yahoo!? Make international calls for as low as $.04/minute with Yahoo! Messenger http://phonecard.yahoo.com/