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=-16.5 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 8A57FC04EB8 for ; Mon, 10 Dec 2018 12:51:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4F19020870 for ; Mon, 10 Dec 2018 12:51:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="tvsXwVCK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4F19020870 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727919AbeLJMv4 (ORCPT ); Mon, 10 Dec 2018 07:51:56 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:40219 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727460AbeLJMvQ (ORCPT ); Mon, 10 Dec 2018 07:51:16 -0500 Received: by mail-wr1-f65.google.com with SMTP id p4so10338492wrt.7 for ; Mon, 10 Dec 2018 04:51:14 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=spp1yx5uWvAgxErNR01vKeP4ipxAKNr5cbWijdqL/NI=; b=tvsXwVCKLmRdJsM+euD1t0rVUHOOn+/ZTTi3MnnQ9yebryAkbI4hvbPXubAR8j9xbT rSzx3Kyplc8mI1Q5cCWawts1mVwnbRT/UG0tp4Xvt5MDVVu5AjP34+MyjU+t6RTFt/1F GtjCSp16Bsb0olrw8ju4ga21oFPvQHFAjGiXj06kBSulY2fBvH1/8yimSxJdEzM0IjDe S2UHXqy/PlTnElD5PvCE/Ei8NOK6WhW4AzfjK1G4NAKHmzILpvArpdT0x23Ci7QVw1Jf siaqLTUGCqHPMIili1iJlbBGd6qfhARL0xDVAgzKR2wFfvkvY0Mi96XrFZLLMJ9KfrPg c6gA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=spp1yx5uWvAgxErNR01vKeP4ipxAKNr5cbWijdqL/NI=; b=GOPElFrY/9yqE2daTKIK9SKsLw31CcLe88LXdkMmsftJIBqzv+SxQoi0M4iE/aM3pH 5b9W21OT1FWBjmZlqb0U/Ji+GZjVYp9DZHT0VGYu8JFL+YVKEDUUaSl5E7NdUGgINs0S Ki/vNc4znlPTMVy19Cm+tYaNbHf9M8btIS0YYuJ9hIyZT23UIi2j3Fflr+Vznvkk3tFz +LKYkbIpgMNq16AaE46GaeEleR3YnXymq/okEBUorf9aTdPCHUjGQuiOYxOt+i8vR1ui qgVh8y18AX+t+2JlLSpjyrJyo3ebKN+Fq/oRBAwl9aXhp+taF0+LbomVp6vOsj/EVGOW czvQ== X-Gm-Message-State: AA+aEWafbW2LDz2tJbgxogKfxOxkQX0dG4Mj2FcykziZdd8UpUVMU63F IjLPfd4FqbHOnTz2XhNoy7bgMA== X-Google-Smtp-Source: AFSGD/WK6voMtzDjeOrD0p0dIVtqA5GSBJDXWoYR6ofaTs6wbsSMRcTZb/d4/4QZpcv/PkUOjr5HNQ== X-Received: by 2002:a5d:684b:: with SMTP id o11mr9182121wrw.316.1544446274117; Mon, 10 Dec 2018 04:51:14 -0800 (PST) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:3180:41f8:3010:ff61]) by smtp.gmail.com with ESMTPSA id l197sm36893363wma.44.2018.12.10.04.51.12 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 10 Dec 2018 04:51:13 -0800 (PST) From: Andrey Konovalov To: Catalin Marinas , Will Deacon , Mark Rutland , Robin Murphy , Kees Cook , Kate Stewart , Greg Kroah-Hartman , Andrew Morton , Ingo Molnar , "Kirill A . Shutemov" , Shuah Khan , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Chintan Pandya , Luc Van Oostenryck , Andrey Konovalov Subject: [PATCH v9 3/8] arm64: untag user addresses in access_ok and __uaccess_mask_ptr Date: Mon, 10 Dec 2018 13:51:00 +0100 Message-Id: <674252952827b57f4259876cd4ddf802f3539356.1544445454.git.andreyknvl@google.com> X-Mailer: git-send-email 2.20.0.rc2.403.gdbc3b29805-goog In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org copy_from_user (and a few other similar functions) are used to copy data from user memory into the kernel memory or vice versa. Since a user can provided a tagged pointer to one of the syscalls that use copy_from_user, we need to correctly handle such pointers. Do this by untagging user pointers in access_ok and in __uaccess_mask_ptr, before performing access validity checks. Reviewed-by: Catalin Marinas Signed-off-by: Andrey Konovalov --- arch/arm64/include/asm/uaccess.h | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h index 3c3864ba3cc1..d28c3b1314ce 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -104,7 +104,8 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si #define untagged_addr(addr) \ ((__typeof__(addr))sign_extend64((u64)(addr), 55)) -#define access_ok(type, addr, size) __range_ok(addr, size) +#define access_ok(type, addr, size) \ + __range_ok(untagged_addr(addr), size) #define user_addr_max get_fs #define _ASM_EXTABLE(from, to) \ @@ -236,7 +237,8 @@ static inline void uaccess_enable_not_uao(void) /* * Sanitise a uaccess pointer such that it becomes NULL if above the - * current addr_limit. + * current addr_limit. In case the pointer is tagged (has the top byte set), + * untag the pointer before checking. */ #define uaccess_mask_ptr(ptr) (__typeof__(ptr))__uaccess_mask_ptr(ptr) static inline void __user *__uaccess_mask_ptr(const void __user *ptr) @@ -244,10 +246,11 @@ static inline void __user *__uaccess_mask_ptr(const void __user *ptr) void __user *safe_ptr; asm volatile( - " bics xzr, %1, %2\n" + " bics xzr, %3, %2\n" " csel %0, %1, xzr, eq\n" : "=&r" (safe_ptr) - : "r" (ptr), "r" (current_thread_info()->addr_limit) + : "r" (ptr), "r" (current_thread_info()->addr_limit), + "r" (untagged_addr(ptr)) : "cc"); csdb(); -- 2.20.0.rc2.403.gdbc3b29805-goog