From patchwork Mon Aug 6 16:40:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10557459 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B84CB13B4 for ; Mon, 6 Aug 2018 16:42:29 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A832429765 for ; Mon, 6 Aug 2018 16:42:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9C7E42981B; Mon, 6 Aug 2018 16:42:29 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.8 required=2.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 35B5B29765 for ; Mon, 6 Aug 2018 16:42:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387625AbeHFSuy (ORCPT ); Mon, 6 Aug 2018 14:50:54 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:37000 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387597AbeHFSux (ORCPT ); Mon, 6 Aug 2018 14:50:53 -0400 Received: by mail-wm0-f66.google.com with SMTP id n11-v6so14971250wmc.2 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=DAk4p/Q8lXp9VLs0vAVGYoV3sN0ORr7Gib18OB9nk0WJV5YtLYPL5yN8Y5DdU6Y9mL KpJgIPR0t0czACqGqjqBVM0DQu2DEvagS5qCUra2kaUOZ9rqqVlmzjRqXLq1VrAtxuOe HZ207J15CDMjeFDAOWeORlfQVbuzrwlI9WtPre4vBiE7M+5BsnIeqcDWzYFLDT1cMtj5 Bp0HpaP22W0SH7L7vsy58DTn5+/myuROQEfQTCBhnghNADD9yoaXTQ6cy0861x/6P1MT FmOnT+krGiJq1xitc4zCMVPUWj8Uufg3n1jWqqY9xexlD1a5S5entKOiz+yDs4Wr0lmZ gywQ== X-Gm-Message-State: AOUpUlHO3zugzwK7z0rfL9AcTiap/gdRvSdPd+K7LxogOj/sjBcSVBS5 itNpNIq9IAFtA0xDSJwd9fte6w== 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 Sender: linux-kselftest-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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();