From patchwork Mon Jan 16 16:50:02 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 9519055 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2BDF7601C3 for ; Mon, 16 Jan 2017 16:50:05 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1818F28174 for ; Mon, 16 Jan 2017 16:50:05 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0A94B2849C; Mon, 16 Jan 2017 16:50:05 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 2F2F528174 for ; Mon, 16 Jan 2017 16:50:04 +0000 (UTC) Received: (qmail 5871 invoked by uid 550); 16 Jan 2017 16:50:02 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Reply-To: kernel-hardening@lists.openwall.com Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 5849 invoked from network); 16 Jan 2017 16:50:01 -0000 Date: Mon, 16 Jan 2017 17:50:02 +0100 From: Greg KH To: kernel-hardening@lists.openwall.com Cc: linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , Thomas Sailer , "Rafael J. Wysocki" , Johan Hovold , Alex Elder , "J. Bruce Fields" , Jeff Layton , David Howells , NeilBrown Message-ID: <20170116165002.GA29693@kroah.com> References: <20170116164944.GA28984@kroah.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20170116164944.GA28984@kroah.com> User-Agent: Mutt/1.7.2 (2016-11-26) Subject: [kernel-hardening] [PATCH 1/3] kmod: make usermodehelper path a const string X-Virus-Scanned: ClamAV using ClamSMTP From: Greg Kroah-Hartman 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 d45c96073afb..426a614e97fe 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;