From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932474Ab1HFAMe (ORCPT ); Fri, 5 Aug 2011 20:12:34 -0400 Received: from cantor2.suse.de ([195.135.220.15]:39767 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932444Ab1HFAM2 (ORCPT ); Fri, 5 Aug 2011 20:12:28 -0400 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Aug 5 17:04:16 2011 Message-Id: <20110806000416.234542165@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Fri, 05 Aug 2011 17:04:04 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Vasiliy Kulikov Subject: [46/50] proc: restrict access to /proc/PID/io In-Reply-To: <20110806000419.GA28392@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.33-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Vasiliy Kulikov commit 1d1221f375c94ef961ba8574ac4f85c8870ddd51 upstream. /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. 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. Signed-off-by: Vasiliy Kulikov Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/proc/base.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2519,6 +2519,9 @@ static int do_io_accounting(struct task_ struct task_io_accounting acct = task->ioac; unsigned long flags; + if (!ptrace_may_access(task, PTRACE_MODE_READ)) + return -EACCES; + if (whole && lock_task_sighand(task, &flags)) { struct task_struct *t = task; @@ -2641,7 +2644,7 @@ static const struct pid_entry tgid_base_ REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations), #endif #ifdef CONFIG_TASK_IO_ACCOUNTING - INF("io", S_IRUGO, proc_tgid_io_accounting), + INF("io", S_IRUSR, proc_tgid_io_accounting), #endif }; @@ -2977,7 +2980,7 @@ static const struct pid_entry tid_base_s REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), #endif #ifdef CONFIG_TASK_IO_ACCOUNTING - INF("io", S_IRUGO, proc_tid_io_accounting), + INF("io", S_IRUSR, proc_tid_io_accounting), #endif };