From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934298AbaKSW2N (ORCPT ); Wed, 19 Nov 2014 17:28:13 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:56046 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756744AbaKSUyB (ORCPT ); Wed, 19 Nov 2014 15:54:01 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Thompson , Rusty Russell Subject: [PATCH 3.17 048/141] param: fix crash on bad kernel arguments Date: Wed, 19 Nov 2014 12:51:11 -0800 Message-Id: <20141119205152.258357286@linuxfoundation.org> X-Mailer: git-send-email 2.1.3 In-Reply-To: <20141119205150.700188369@linuxfoundation.org> References: <20141119205150.700188369@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Daniel Thompson commit 3438cf549d2f3ee8e52c82acc8e2a9710ac21a5b upstream. Currently if the user passes an invalid value on the kernel command line then the kernel will crash during argument parsing. On most systems this is very hard to debug because the console hasn't been initialized yet. This is a regression due to commit 51e158c12aca ("param: hand arguments after -- straight to init") which, in response to the systemd debug controversy, made it possible to explicitly pass arguments to init. To achieve this parse_args() was extended from simply returning an error code to returning a pointer. Regretably the new init args logic does not perform a proper validity check on the pointer resulting in a crash. This patch fixes the validity check. Should the check fail then no arguments will be passed to init. This is reasonable and matches how the kernel treats its own arguments (i.e. no error recovery). Signed-off-by: Daniel Thompson Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman --- init/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/init/main.c +++ b/init/main.c @@ -544,7 +544,7 @@ asmlinkage __visible void __init start_k static_command_line, __start___param, __stop___param - __start___param, -1, -1, &unknown_bootoption); - if (after_dashes) + if (!IS_ERR_OR_NULL(after_dashes)) parse_args("Setting init args", after_dashes, NULL, 0, -1, -1, set_init_arg);