From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964821Ab2CMA50 (ORCPT ); Mon, 12 Mar 2012 20:57:26 -0400 Received: from mail.windriver.com ([147.11.1.11]:47779 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758680Ab2CMAWh (ORCPT ); Mon, 12 Mar 2012 20:22:37 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Linus Torvalds , Paul Gortmaker Subject: [34-longterm 081/196] proc: do proper range check on readdir offset Date: Mon, 12 Mar 2012 20:19:54 -0400 Message-Id: <1331598109-31424-36-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.9.3 In-Reply-To: <1331598109-31424-1-git-send-email-paul.gortmaker@windriver.com> References: <1331597724-31358-1-git-send-email-paul.gortmaker@windriver.com> <1331598109-31424-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Linus Torvalds ------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. ------------------- commit d8bdc59f215e62098bc5b4256fd9928bf27053a1 upstream. Rather than pass in some random truncated offset to the pid-related functions, check that the offset is in range up-front. This is just cleanup, the previous commit fixed the real problem. Signed-off-by: Linus Torvalds Signed-off-by: Paul Gortmaker --- fs/proc/base.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/proc/base.c b/fs/proc/base.c index 8418fcc..268f00d 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2871,11 +2871,16 @@ static int proc_pid_fill_cache(struct file *filp, void *dirent, filldir_t filldi /* for the /proc/ directory itself, after non-process stuff has been done */ int proc_pid_readdir(struct file * filp, void * dirent, filldir_t filldir) { - unsigned int nr = filp->f_pos - FIRST_PROCESS_ENTRY; - struct task_struct *reaper = get_proc_task(filp->f_path.dentry->d_inode); + unsigned int nr; + struct task_struct *reaper; struct tgid_iter iter; struct pid_namespace *ns; + if (filp->f_pos >= PID_MAX_LIMIT + TGID_OFFSET) + goto out_no_task; + nr = filp->f_pos - FIRST_PROCESS_ENTRY; + + reaper = get_proc_task(filp->f_path.dentry->d_inode); if (!reaper) goto out_no_task; -- 1.7.9.3