From patchwork Tue Nov 5 20:58:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 11228651 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id ADB1413A4 for ; Tue, 5 Nov 2019 21:11:49 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 807692087E for ; Tue, 5 Nov 2019 21:11:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Ek13ETMi"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ysUUjqjG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 807692087E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=2ger3PKUS61hJ+eYN+hCFRdojoA7Xq7AZcq8EYZJ3kk=; b=Ek13ETMi3SUGQjZwedBx032Fvr XKG4SoaZEIlC9UPhOg3WTFRLN+efy4pRRgPCg1er0cXgqAhYUARzaZ23UvtIU8tVX/O/IDCsHPQ9d ESrQE9G4YBm9u2Tisl8+t8yT31G1zRhTsbpXLxjop7zJG+Q4QoTYGhtS2rdWcDZTU/QoiCzrs6HJp FgUYixhSdU4yihMk5Kw0MkqtMtFeUW13w0icHpdrYimjbcEN/2Mli2QpxBn/Hsj4euAlnjtASRHrK FWK+RGvLq4UPERR4fUv+qmJZ2gXNoGzhGBqTuYH5PPfyhmCYB7uPPkyR5B52MczyA5UFB/lCeW1bV YqbW7MpA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iS679-0003sY-Du; Tue, 05 Nov 2019 21:11:47 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iS5wr-0008Hq-4w for linux-arm-kernel@lists.infradead.org; Tue, 05 Nov 2019 21:01:11 +0000 Received: from e123331-lin.home (lfbn-mar-1-643-104.w90-118.abo.wanadoo.fr [90.118.215.104]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B8D0721A49; Tue, 5 Nov 2019 21:01:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572987668; bh=FetzsmBKcHG3noVVeRiqwAXnFXG1rG/FriFnvmo3oVg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ysUUjqjGqjW7pXg3D6+E0Jg5HcjlsCa4gH2J6vvnieu9zVN++CgLHAU2BIXgHM2Kv UBpJZ2gjdgTX2xcjDC/50prFoAFJcM9M1+fsFTjf02htMosLZNseuokBq+KhG1FR4L tIT97Zq5KcT7mIfm8JyMU1sTu3fJX1ttT0WDL2F8= From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Subject: [PATCH for-stable-v4.4 45/53] ARM: 8796/1: spectre-v1, v1.1: provide helpers for address sanitization Date: Tue, 5 Nov 2019 21:58:38 +0100 Message-Id: <20191105205846.1394-46-ardb@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191105205846.1394-1-ardb@kernel.org> References: <20191105205846.1394-1-ardb@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191105_130109_264436_6C424549 X-CRM114-Status: GOOD ( 13.90 ) X-Spam-Score: -5.2 (-----) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (-5.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at https://www.dnswl.org/, high trust [198.145.29.99 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Sasha Levin , Florian Fainelli , Julien Thierry , Tony Lindgren , Catalin Marinas , Russell King , "David A . Long" , Marc Zyngier , Will Deacon , Ard Biesheuvel MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Julien Thierry Commit afaf6838f4bc896a711180b702b388b8cfa638fc upstream. Introduce C and asm helpers to sanitize user address, taking the address range they target into account. Use asm helper for existing sanitization in __copy_from_user(). Signed-off-by: Julien Thierry Signed-off-by: Russell King Signed-off-by: David A. Long Reviewed-by: Julien Thierry Signed-off-by: Sasha Levin Signed-off-by: Ard Biesheuvel --- arch/arm/include/asm/assembler.h | 11 +++++++++ arch/arm/include/asm/uaccess.h | 26 ++++++++++++++++++++ arch/arm/lib/copy_from_user.S | 6 +---- 3 files changed, 38 insertions(+), 5 deletions(-) diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 483481c6937e..f2624fbd0336 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -461,6 +461,17 @@ THUMB( orr \reg , \reg , #PSR_T_BIT ) #endif .endm + .macro uaccess_mask_range_ptr, addr:req, size:req, limit:req, tmp:req +#ifdef CONFIG_CPU_SPECTRE + sub \tmp, \limit, #1 + subs \tmp, \tmp, \addr @ tmp = limit - 1 - addr + addhs \tmp, \tmp, #1 @ if (tmp >= 0) { + subhss \tmp, \tmp, \size @ tmp = limit - (addr + size) } + movlo \addr, #0 @ if (tmp < 0) addr = NULL + csdb +#endif + .endm + .macro uaccess_disable, tmp, isb=1 #ifdef CONFIG_CPU_SW_DOMAIN_PAN /* diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h index 98bbf89763a6..9ae610bf5234 100644 --- a/arch/arm/include/asm/uaccess.h +++ b/arch/arm/include/asm/uaccess.h @@ -137,6 +137,32 @@ static inline void set_fs(mm_segment_t fs) #define __inttype(x) \ __typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL)) +/* + * Sanitise a uaccess pointer such that it becomes NULL if addr+size + * is above the current addr_limit. + */ +#define uaccess_mask_range_ptr(ptr, size) \ + ((__typeof__(ptr))__uaccess_mask_range_ptr(ptr, size)) +static inline void __user *__uaccess_mask_range_ptr(const void __user *ptr, + size_t size) +{ + void __user *safe_ptr = (void __user *)ptr; + unsigned long tmp; + + asm volatile( + " sub %1, %3, #1\n" + " subs %1, %1, %0\n" + " addhs %1, %1, #1\n" + " subhss %1, %1, %2\n" + " movlo %0, #0\n" + : "+r" (safe_ptr), "=&r" (tmp) + : "r" (size), "r" (current_thread_info()->addr_limit) + : "cc"); + + csdb(); + return safe_ptr; +} + /* * Single-value transfer routines. They automatically use the right * size if we just have the right pointer type. Note that the functions diff --git a/arch/arm/lib/copy_from_user.S b/arch/arm/lib/copy_from_user.S index d36329cefedc..e32b51838439 100644 --- a/arch/arm/lib/copy_from_user.S +++ b/arch/arm/lib/copy_from_user.S @@ -93,11 +93,7 @@ ENTRY(arm_copy_from_user) #ifdef CONFIG_CPU_SPECTRE get_thread_info r3 ldr r3, [r3, #TI_ADDR_LIMIT] - adds ip, r1, r2 @ ip=addr+size - sub r3, r3, #1 @ addr_limit - 1 - cmpcc ip, r3 @ if (addr+size > addr_limit - 1) - movcs r1, #0 @ addr = NULL - csdb + uaccess_mask_range_ptr r1, r2, r3, ip #endif #include "copy_template.S"