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=-10.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_MED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 98CE5C46471 for ; Mon, 6 Aug 2018 16:42:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 532CA21A67 for ; Mon, 6 Aug 2018 16:42:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="hY19VVlN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 532CA21A67 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 S2387638AbeHFSuy (ORCPT ); Mon, 6 Aug 2018 14:50:54 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:33690 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387596AbeHFSux (ORCPT ); Mon, 6 Aug 2018 14:50:53 -0400 Received: by mail-wm0-f68.google.com with SMTP id r24-v6so12002076wmh.0 for ; Mon, 06 Aug 2018 09:40:59 -0700 (PDT) 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=WADZVauYt2+vN10op76v0l4/uhmUIRsYzVe9gnbEQFA=; b=hY19VVlNC+aT5T0+2ijd0mPFjapVd6gfqUj0erw0EDOJ7eBmW+Z2x+XRfZD5O4Ac94 3I63n27oCUcp10sI/R6BhxKri6mPzwVCDsDOb3SWT19hUTxakDBMMYxpjSdnaqFuVuLc bpml4I6XJiFT2ngv+DVV9M2GX/Dx2Z7qOxaYHLhvHwuI7CE/9/5OFZL5C0FrKLsuBTup FKle1LaLfIHzrfWzOuj2ESOMv/mfS1XGNWkuASeMkcTFIcbmIBjb+9eD3ytrtzihsmpN Eh26t1BM3+6TAUjrYud29s8Qagu0ISZ3YeQG4hAkl/UkhkQfGbdL32tE8/Q1VI+PBaAb MdHg== 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=WADZVauYt2+vN10op76v0l4/uhmUIRsYzVe9gnbEQFA=; b=uhlR/U1OJqOC5p57zHN2HASX3VA2ANl6lPRstjEhYYq33SWXEnTj2zUEseqX8UkQr3 HzLbFj5xBGigmbdmCrrcjytIFr7DRYC+6JrqhVri7ZbX1HRxilv/H1IpMHCIesNLgBoZ PSlvEKAeLSnIWQ6DkQgcNfFaBmFpkqVfZESt3Vx3qdDXyzKLlwbEW6AdWJUOJ9nvhWkq 1BDPKC8QuIbX7LH/QeyFnacEjmtfl1uc0FCwL6kyglMIJYtyFArwXpNVxPGz1cHnqtcw iIChpWGrWzHZV6oBkX3v3YjGQzRJLg1BR0fSsvSwHZTa6npDdHytnkQQC+nJIxuCBGwf 63iQ== X-Gm-Message-State: AOUpUlFUjmv0qDZVbLVIoyMOk4U1fLgaKWN4CtjEvDD/5zY1eRaM26Bi RXs5wbMEiRRJO2PvnhSTO7i5vg== X-Google-Smtp-Source: AAOMgpckRAYy9vorc4eMVCQ1Uc5x51WbaAcr5KT0f6sPPmsBT/dX4REx1PziWt7qxPnzxNWYQXu1Yw== X-Received: by 2002:a1c:3314:: with SMTP id z20-v6mr11558447wmz.95.1533573657895; Mon, 06 Aug 2018 09:40:57 -0700 (PDT) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:84be:a42a:826d:c530]) by smtp.gmail.com with ESMTPSA id 66-v6sm16385790wmw.34.2018.08.06.09.40.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 Aug 2018 09:40:57 -0700 (PDT) From: Andrey Konovalov To: Catalin Marinas , Will Deacon , Mark Rutland , Robin Murphy , Al Viro , Andrey Konovalov , 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 Subject: [PATCH v5 03/10] arm64: untag user addresses in access_ok and __uaccess_mask_ptr Date: Mon, 6 Aug 2018 18:40:38 +0200 Message-Id: X-Mailer: git-send-email 2.18.0.597.ga71716f1ad-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. 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 2d6451cbaa86..fa7318d3d7d5 100644 --- a/arch/arm64/include/asm/uaccess.h +++ b/arch/arm64/include/asm/uaccess.h @@ -105,7 +105,8 @@ 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) \ @@ -237,7 +238,8 @@ 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) @@ -245,10 +247,11 @@ 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(); -- 2.18.0.597.ga71716f1ad-goog