From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751185AbVI1JZ7 (ORCPT ); Wed, 28 Sep 2005 05:25:59 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751058AbVI1JZ7 (ORCPT ); Wed, 28 Sep 2005 05:25:59 -0400 Received: from sv1.valinux.co.jp ([210.128.90.2]:42166 "EHLO sv1.valinux.co.jp") by vger.kernel.org with ESMTP id S1750813AbVI1JZ7 (ORCPT ); Wed, 28 Sep 2005 05:25:59 -0400 Date: Wed, 28 Sep 2005 18:25:58 +0900 From: KUROSAWA Takahiro To: KUROSAWA Takahiro Cc: pj@sgi.com, taka@valinux.co.jp, magnus.damm@gmail.com, dino@in.ibm.com, linux-kernel@vger.kernel.org, ckrm-tech@lists.sourceforge.net Subject: [PATCH][BUG] fix memory leak on reading cpuset files after seeking beyond eof In-Reply-To: <20050927113902.C78A570046@sv1.valinux.co.jp> References: <20050908225539.0bc1acf6.pj@sgi.com> <20050909.203849.33293224.taka@valinux.co.jp> <20050909063131.64dc8155.pj@sgi.com> <20050910.161145.74742186.taka@valinux.co.jp> <20050910015209.4f581b8a.pj@sgi.com> <20050926093432.9975870043@sv1.valinux.co.jp> <20050927013751.47cbac8b.pj@sgi.com> <20050927113902.C78A570046@sv1.valinux.co.jp> X-Mailer: Sylpheed version 2.1.2+svn (GTK+ 2.6.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-Id: <20050928092558.61F6170041@sv1.valinux.co.jp> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 27 Sep 2005 20:39:02 +0900 KUROSAWA Takahiro wrote: > On Tue, 27 Sep 2005 01:37:51 -0700 > Paul Jackson wrote: > > > The above reminds me of a bug fix that you provided in the previous > > patch set, for the case *ppos >= eof. I wonder if we have duplicated > > code here. > Ah, yes, we need to fix the bug in the cpuset code introduced by me... I fixed the bug. Sorry for my previous incomplete patch. The following patch is against linux-2.6.14-rc2. Signed-off-by: KUROSAWA Takahiro --- from-0001/kernel/cpuset.c +++ to-work/kernel/cpuset.c 2005-09-28 17:42:00.759401736 +0900 @@ -969,7 +969,7 @@ static ssize_t cpuset_common_file_read(s ssize_t retval = 0; char *s; char *start; - size_t n; + ssize_t n; if (!(page = (char *)__get_free_page(GFP_KERNEL))) return -ENOMEM; @@ -999,12 +999,13 @@ static ssize_t cpuset_common_file_read(s *s++ = '\n'; *s = '\0'; - /* Do nothing if *ppos is at the eof or beyond the eof. */ - if (s - page <= *ppos) - return 0; - start = page + *ppos; n = s - start; + + /* Do nothing if *ppos is at the eof or beyond the eof. */ + if (n <= 0) + goto out; + retval = n - copy_to_user(buf, start, min(n, nbytes)); *ppos += retval; out: