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=-16.4 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,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 8A72CC43143 for ; Tue, 2 Oct 2018 13:12:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 510BC206B2 for ; Tue, 2 Oct 2018 13:12:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="uOQ+FfmU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 510BC206B2 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 S1728051AbeJBT4K (ORCPT ); Tue, 2 Oct 2018 15:56:10 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:36623 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727975AbeJBT4I (ORCPT ); Tue, 2 Oct 2018 15:56:08 -0400 Received: by mail-wm1-f67.google.com with SMTP id n23-v6so2155496wmc.1 for ; Tue, 02 Oct 2018 06:12:51 -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=UwxTkI+pYsHu40iHWOY4wB/R27fPZGDmoFBeZbslwgQ=; b=uOQ+FfmUC+RaS3QyuW/9cJe9RH7pk1ltGJ/08pMGtCZU0scrsbZfvGCfzNFlnYWeR5 g4Vr9xESUkQ3uzvvWZq0xdqiM4GWXtOzvpTeiJAGBAFrgtHYW5APJNvA76dSQYg6AQ6U +HnGxnOWKMtPLutPQOCuJNs520+lOBa8RK6H5554UVrF0vYcw9e7fDpm51uyEaclf9he mlrY9jl92q9OeuR3mYmCoOs+LQInROEeHRG03TikcJ97tIw0t2mAJ68JeLA3lwRgRJ8x Pq5kHnJz2EmX3aXhV7wv8Shr2/YuRwwklttZlbsqxMfB4W5wvp501g+TByqSV28przNS TNVw== 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=UwxTkI+pYsHu40iHWOY4wB/R27fPZGDmoFBeZbslwgQ=; b=mgGxGDhuYlGb2qrvEcz4+R3X3aCpUHe5CQQ66hsxMNUt9aRzf2wOGjXWwXkQvguhF1 35weZu0sLZVs9WWIAFZUJl7f7QSERtlDpxBN621PbEso+SS+KXmQJ7e86YaXlnIb5S/l DoYW2XMUQQY7BOGjH5YMtzt7Eaf/e1UxvEElutkeldcgW3vEDF8KCVDoPvlDkZ9QIAu1 5aX9c6/+1NMliHRV0gudFb2QSKsHbNfb5SuBOfRjk08QwnLEYjdAQj7kvyAdirJ/4+0H cWPZJIBTs0YENAzCv1/eMXjwJHe3jzaNexgjBul2Uc/nG+wTnJTRU55Ua0pgOykDFASD fSDA== X-Gm-Message-State: ABuFfohyMajUEBVT+Qyt3Jeqt3mvvoiY9Dh+T7pZQYCXQ01uCeKvVlQw b1qd9gFkIRg+eHAyZNECFp4twA== X-Google-Smtp-Source: ACcGV622sDyFt3S8csEmXThpDBNFNMvaRauKoxqXv/A4k50G/uwAP10xj9S7JvVx/Gl6W/hzjmgNeA== X-Received: by 2002:a1c:d4b:: with SMTP id 72-v6mr1969892wmn.102.1538485970324; Tue, 02 Oct 2018 06:12:50 -0700 (PDT) Received: from andreyknvl0.muc.corp.google.com ([2a00:79e0:15:10:84be:a42a:826d:c530]) by smtp.gmail.com with ESMTPSA id v10-v6sm17458681wrp.0.2018.10.02.06.12.49 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Oct 2018 06:12:49 -0700 (PDT) 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 v7 3/8] arm64: untag user addresses in access_ok and __uaccess_mask_ptr Date: Tue, 2 Oct 2018 15:12:38 +0200 Message-Id: <2b957e4f0a3133480dda9d9c8aeceb9b9d9378eb.1538485901.git.andreyknvl@google.com> X-Mailer: git-send-email 2.19.0.605.g01d371f741-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(); -- 2.19.0.605.g01d371f741-goog