From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2C500C10F0E for ; Thu, 18 Apr 2019 18:16:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E6AF720675 for ; Thu, 18 Apr 2019 18:16:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555611411; bh=kwDrbQ7Pdr5H1ZaQorcBxzavuMiV3zDRLEMzrrWthx4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=biJ+mMu43WHvjiiIpDPIUC37pugUdv6ZnuAvpCCiJr8/AMGMGJ6tmyzUxFzFRP9Mq rJl0s6ID0pkv6klJVUg5u0CI0c+Y1Y83hNIEJT6TPsyJr56ZEWnMWaMh4Af9WlZr8v MA4UdAdPs6A5SJGKGl40wqj585SMxe8Ps7OvScF4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404250AbfDRSLe (ORCPT ); Thu, 18 Apr 2019 14:11:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:41140 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403910AbfDRSJa (ORCPT ); Thu, 18 Apr 2019 14:09:30 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DD9E421871; Thu, 18 Apr 2019 18:09:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555610969; bh=kwDrbQ7Pdr5H1ZaQorcBxzavuMiV3zDRLEMzrrWthx4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UckUm16PniVxhqOqK6Eb5KLZ30+GhaX4GnwtLQkPt/Tt1CiRPhEph/dryCR6c04RH Bnk4my2UOG/+4PfLvwLs/DKgk4iytqcT9FqlpNj/urm3+2qpaQCCvVZCSzQczTApbF MC/hMDiJM5KCR4FI8RsFOy6n5jW9T9OOTQwJvIYs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Eugeniy Paltsev , Vineet Gupta , Sasha Levin Subject: [PATCH 5.0 01/93] ARC: u-boot args: check that magic number is correct Date: Thu, 18 Apr 2019 19:56:39 +0200 Message-Id: <20190418160436.924268700@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190418160436.781762249@linuxfoundation.org> References: <20190418160436.781762249@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit edb64bca50cd736c6894cc6081d5263c007ce005 ] In case of devboards we really often disable bootloader and load Linux image in memory via JTAG. Even if kernel tries to verify uboot_tag and uboot_arg there is sill a chance that we treat some garbage in registers as valid u-boot arguments in JTAG case. E.g. it is enough to have '1' in r0 to treat any value in r2 as a boot command line. So check that magic number passed from u-boot is correct and drop u-boot arguments otherwise. That helps to reduce the possibility of using garbage as u-boot arguments in JTAG case. We can safely check U-boot magic value (0x0) in linux passed via r1 register as U-boot pass it from the beginning. So there is no backward-compatibility issues. Signed-off-by: Eugeniy Paltsev Signed-off-by: Vineet Gupta Signed-off-by: Sasha Levin --- arch/arc/kernel/head.S | 1 + arch/arc/kernel/setup.c | 8 ++++++++ 2 files changed, 9 insertions(+) diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S index 30e090625916..a72bbda2f7aa 100644 --- a/arch/arc/kernel/head.S +++ b/arch/arc/kernel/head.S @@ -106,6 +106,7 @@ ENTRY(stext) ; r2 = pointer to uboot provided cmdline or external DTB in mem ; These are handled later in handle_uboot_args() st r0, [@uboot_tag] + st r1, [@uboot_magic] st r2, [@uboot_arg] ; setup "current" tsk and optionally cache it in dedicated r25 diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c index 7b2340996cf8..7b3a7b3b380c 100644 --- a/arch/arc/kernel/setup.c +++ b/arch/arc/kernel/setup.c @@ -36,6 +36,7 @@ unsigned int intr_to_DE_cnt; /* Part of U-boot ABI: see head.S */ int __initdata uboot_tag; +int __initdata uboot_magic; char __initdata *uboot_arg; const struct machine_desc *machine_desc; @@ -497,6 +498,8 @@ static inline bool uboot_arg_invalid(unsigned long addr) #define UBOOT_TAG_NONE 0 #define UBOOT_TAG_CMDLINE 1 #define UBOOT_TAG_DTB 2 +/* We always pass 0 as magic from U-boot */ +#define UBOOT_MAGIC_VALUE 0 void __init handle_uboot_args(void) { @@ -511,6 +514,11 @@ void __init handle_uboot_args(void) goto ignore_uboot_args; } + if (uboot_magic != UBOOT_MAGIC_VALUE) { + pr_warn(IGNORE_ARGS "non zero uboot magic\n"); + goto ignore_uboot_args; + } + if (uboot_tag != UBOOT_TAG_NONE && uboot_arg_invalid((unsigned long)uboot_arg)) { pr_warn(IGNORE_ARGS "invalid uboot arg: '%px'\n", uboot_arg); -- 2.19.1