From patchwork Tue Apr 30 13:24:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 10923619 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 C9F07933 for ; Tue, 30 Apr 2019 13:27:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BA15A2860A for ; Tue, 30 Apr 2019 13:27:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AE18528A63; Tue, 30 Apr 2019 13:27:56 +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=-15.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, USER_IN_DEF_DKIM_WL autolearn=ham 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 516BE27EE2 for ; Tue, 30 Apr 2019 13:27:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728168AbfD3NZb (ORCPT ); Tue, 30 Apr 2019 09:25:31 -0400 Received: from mail-vk1-f202.google.com ([209.85.221.202]:47571 "EHLO mail-vk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728070AbfD3NZ2 (ORCPT ); Tue, 30 Apr 2019 09:25:28 -0400 Received: by mail-vk1-f202.google.com with SMTP id x77so1448945vke.14 for ; Tue, 30 Apr 2019 06:25:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=BvUTfQkQM7uCDeEtImKKI/2Hme2ZprNLcMmbkGV4djo=; b=dpVTwFKbchbVkkb84ng8BnoHNS2SM91wquNJtuly6Sbp7lXj1bPrbJBiP3SyhTU0xP LuA/DNrbjhKI/dHi3IXFK1lS8O09Sk1+qA/R7rjDLupO2W7Szy3T1dELXK4hEpZqkwPw qD0yKLxb8ZjzpYALNjI1z0dDf4TB8V0IRIOptCx1gDVu9+jOblt+XzKkwvlPuV63pqHj wnFsYt5mNXo/Rj6N9Lo9JMQODsljOWPF/MJrAcRLfdznXkGZCgNmaSrk7MrXtOUREZGb X2QTJ1/W011vEIe5OofpK81AMWPuQy4lXPQltspauNse0OruElYuf2mJ90h6FolZJ8lL VpnA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=BvUTfQkQM7uCDeEtImKKI/2Hme2ZprNLcMmbkGV4djo=; b=mX6acSFcZki/9xh9mnmfroathFOIXwTOUE9JJTVhNZ6R1qMevaPIRrgivWwtATdjdw RM3F9DnktUcVqKEbiWgt6XwYl+w5N+8smwT8+DYdGhtgRf8kjn0PFnHSogmwjtbp61CX 8Zbyg/r44qCqDzNNSUefDj4MxaTq7joOa1BomWwvPEdT7N+8R3n5N0w4g6BHTcttw8O+ Vf93yEeEnGGM6mJDYLOTxAPlZjV/qkmTyj2ObliiXbHPmm1KCBgibmwLq1VgU4PA5m9s wlZ5H+fjyhEPYndmuIK5Vj0EQzfG20JRWKhbpSB1CaUj3X1lrDDp1WC3N60GzSDnwcUe yo4A== X-Gm-Message-State: APjAAAUI7VPydBIcgb4+mIPdNEkXCnb/CqBtCRYbiGza5nGAfSUxPQE7 Xv1vX2OyUqVDkP8lLdoVbQvyNohYZHQmZClE X-Google-Smtp-Source: APXvYqyRA/Qu4LKAWcvJoaQQlsyyIllouYjqkXgAFh5vrZ+95OMG6R4QdBb3NSzDXJSn7wdUrbj4M88LAp+D5Hqp X-Received: by 2002:a67:ea83:: with SMTP id f3mr2107513vso.59.1556630726654; Tue, 30 Apr 2019 06:25:26 -0700 (PDT) Date: Tue, 30 Apr 2019 15:24:59 +0200 In-Reply-To: Message-Id: <6f38f610cc22dca9aef05d53a5a94b24763cc628.1556630205.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.593.g511ec345e18-goog Subject: [PATCH v14 03/17] lib, arm64: untag user pointers in strn*_user From: Andrey Konovalov To: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Catalin Marinas , Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Kees Cook , Yishai Hadas , Kuehling@google.com, Felix , Deucher@google.com, Alexander , Koenig@google.com, Christian , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , Chintan Pandya , Luc Van Oostenryck , Dave Martin , Kevin Brodsky , Szabolcs Nagy , Andrey Konovalov Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch is a part of a series that extends arm64 kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. strncpy_from_user and strnlen_user accept user addresses as arguments, and do not go through the same path as copy_from_user and others, so here we need to handle the case of tagged user addresses separately. Untag user pointers passed to these functions. Note, that this patch only temporarily untags the pointers to perform validity checks, but then uses them as is to perform user memory accesses. Signed-off-by: Andrey Konovalov --- lib/strncpy_from_user.c | 3 ++- lib/strnlen_user.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c index 58eacd41526c..6209bb9507c7 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include @@ -107,7 +108,7 @@ long strncpy_from_user(char *dst, const char __user *src, long count) return 0; max_addr = user_addr_max(); - src_addr = (unsigned long)src; + src_addr = (unsigned long)untagged_addr(src); if (likely(src_addr < max_addr)) { unsigned long max = max_addr - src_addr; long retval; diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c index 1c1a1b0e38a5..8ca3d2ac32ec 100644 --- a/lib/strnlen_user.c +++ b/lib/strnlen_user.c @@ -2,6 +2,7 @@ #include #include #include +#include #include @@ -109,7 +110,7 @@ long strnlen_user(const char __user *str, long count) return 0; max_addr = user_addr_max(); - src_addr = (unsigned long)str; + src_addr = (unsigned long)untagged_addr(str); if (likely(src_addr < max_addr)) { unsigned long max = max_addr - src_addr; long retval;