From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753803AbcLNSuU (ORCPT ); Wed, 14 Dec 2016 13:50:20 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:42300 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753244AbcLNSuS (ORCPT ); Wed, 14 Dec 2016 13:50:18 -0500 Date: Wed, 14 Dec 2016 10:50:28 -0800 From: Greg KH To: kernel-hardening@lists.openwall.com Cc: linux-kernel@vger.kernel.org Subject: [PATCH 1/4] kmod: make usermodehelper path a const string Message-ID: <20161214185028.GA4939@kroah.com> References: <20161214185000.GA3930@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161214185000.GA3930@kroah.com> User-Agent: Mutt/1.7.2 (2016-11-26) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is in preparation for making it so that usermode helper programs can't be changed, if desired, by userspace. We will tackle the mess of cleaning up the write-ability of argv and env later, that's going to take more work, for much less gain... Signed-off-by: Greg Kroah-Hartman --- include/linux/kmod.h | 7 ++++--- kernel/kmod.c | 4 ++-- 2 files changed, 6 insertions(+), 5 deletions(-) diff --git a/include/linux/kmod.h b/include/linux/kmod.h index fcfd2bf14d3f..c4e441e00db5 100644 --- a/include/linux/kmod.h +++ b/include/linux/kmod.h @@ -56,7 +56,7 @@ struct file; struct subprocess_info { struct work_struct work; struct completion *complete; - char *path; + const char *path; char **argv; char **envp; int wait; @@ -67,10 +67,11 @@ struct subprocess_info { }; extern int -call_usermodehelper(char *path, char **argv, char **envp, int wait); +call_usermodehelper(const char *path, char **argv, char **envp, int wait); extern struct subprocess_info * -call_usermodehelper_setup(char *path, char **argv, char **envp, gfp_t gfp_mask, +call_usermodehelper_setup(const char *path, char **argv, char **envp, + gfp_t gfp_mask, int (*init)(struct subprocess_info *info, struct cred *new), void (*cleanup)(struct subprocess_info *), void *data); diff --git a/kernel/kmod.c b/kernel/kmod.c index 0277d1216f80..0c216b76afca 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -516,7 +516,7 @@ static void helper_unlock(void) * Function must be runnable in either a process context or the * context in which call_usermodehelper_exec is called. */ -struct subprocess_info *call_usermodehelper_setup(char *path, char **argv, +struct subprocess_info *call_usermodehelper_setup(const char *path, char **argv, char **envp, gfp_t gfp_mask, int (*init)(struct subprocess_info *info, struct cred *new), void (*cleanup)(struct subprocess_info *info), @@ -613,7 +613,7 @@ EXPORT_SYMBOL(call_usermodehelper_exec); * This function is the equivalent to use call_usermodehelper_setup() and * call_usermodehelper_exec(). */ -int call_usermodehelper(char *path, char **argv, char **envp, int wait) +int call_usermodehelper(const char *path, char **argv, char **envp, int wait) { struct subprocess_info *info; gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL; -- 2.10.2