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=-16.6 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=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 C89BBC04AA6 for ; Tue, 30 Apr 2019 13:25:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 99FAF21734 for ; Tue, 30 Apr 2019 13:25:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="dpVTwFKb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728268AbfD3NZe (ORCPT ); Tue, 30 Apr 2019 09:25:34 -0400 Received: from mail-vk1-f202.google.com ([209.85.221.202]:43799 "EHLO mail-vk1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728059AbfD3NZ2 (ORCPT ); Tue, 30 Apr 2019 09:25:28 -0400 Received: by mail-vk1-f202.google.com with SMTP id h7so2612691vkf.10 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=mbxJNn+a58PueIozb635dJH4i9bJZklW0AHRQ6ih7BRcHLjbwT+ItZVbuyKttmCacW nA3LwUOF5veRis4g1YCF/SHsfP+ZccsUpY5S2Fq5zu6sKphgl1wm2voBQfDBubD10pBv WXKZsp6WzudbFx+rkAvX33WyhfvGoA1XODPRr236WLpGcN+8xyrzotzh7r4qyTdSFPLI /LlsuUa3pbrtF0bkCx15SfH092e4JDerUBBQAmhx+eZ/4i6fHd2uEaf76fFgR4q+fRow ZGiIvokqGYbIzRFOv2Tzl7uZYwXaBiu6zwFVW8YFqzX+vHwf0IVKQbHC9IeIlLT1pNBC wjjg== X-Gm-Message-State: APjAAAU2+dNSMFmnjC9NfgUI6l9uMTWjrbE/78RP59k4/TqUHDW3GAgM dtvrHc/+wss6THSHOiU1E7dDXhNAgpQ4WHp5 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 Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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; -- 2.21.0.593.g511ec345e18-goog