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 CC0F1C43381 for ; Wed, 20 Mar 2019 14:51:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A08AC218AC for ; Wed, 20 Mar 2019 14:51:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="gbUaG2SU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728385AbfCTOv4 (ORCPT ); Wed, 20 Mar 2019 10:51:56 -0400 Received: from mail-pg1-f202.google.com ([209.85.215.202]:33250 "EHLO mail-pg1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728367AbfCTOvy (ORCPT ); Wed, 20 Mar 2019 10:51:54 -0400 Received: by mail-pg1-f202.google.com with SMTP id y1so2935677pgo.0 for ; Wed, 20 Mar 2019 07:51:53 -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=k1ksHzqcIFCs0rlhYrsau26vl3ocVueBBoKnHNKxr50=; b=gbUaG2SUmK0LgYPWKNjtqqNqra0Dj2I7PW9z90Jwp3BbFr6Ygh4VDAsBxA5gDOongd +7CxcUNls+IlKo+JGYjfKyQrfYRtO4Z47SxpoLW/8mbPq3NLKcCBVFUfMf1O6lo5lyQS Xjgdf+hI7Y/bA1D0SA8rH8Eu8XxBhdBy5VVMEbbfPWY8xA3Sb5oG0H4SEAubrB034XoX QEsR92P8+ORdJnszt4DIVx7Fa/WP9kGWpGO4+l3UfQFEGOIoLoqxYh83b5fPG2to4T2Y zFPE52PhA9pJC7TqxInYx4207DCj5+fCOTEW3biD/iclPyCXcoUirtevwOL47SHpdgsx zTpA== 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=k1ksHzqcIFCs0rlhYrsau26vl3ocVueBBoKnHNKxr50=; b=Crkw32t90ftuCCaqRP1BhWfCoTVPsIT9KZLVIc1Z+7EgGRsUumf2Ih923OLjBCrUAh 0KcphVr8Bb47tH9Bpy8zlomdXBBEJz9vA1oKPOFy6SVLY7zyuRxqYE/beGx8o9t8e4DH ZgnDwbkEwW1NabMTi0Bf8qmuU/nW01Y1ySWSC3mZPiZLm+LuPwLrQtal4C4M7bxvjl5s MsO+4O3K/e8b6ACvqrZ9PAnVaJsa8xQpXoY2TtzY1Ynd+dv+5XRtWxhejBnjEr2FmdN/ lqIk98zw+CKf2dGyWeMc8gyvGFQf4unFhpqUmbtYMJfb6V3/V3YXBnypywi+LmyY4SFM 7huQ== X-Gm-Message-State: APjAAAVfER8wCR2X6is5QgrbfoVoMOGCw52bW4oOkakmSIzwGuRVXO1b nL7ld42yob9NLm53vqpADwacxYl8rDKyIkHt X-Google-Smtp-Source: APXvYqyDQEPwUnTSsgi/gUBKfoSs2QhRiDzA2VJUjgLM5tdiS/YJBnhxYd/PCUUZbtlvisMRP7lT9bGN6AETareo X-Received: by 2002:a63:2ac2:: with SMTP id q185mr3933097pgq.119.1553093512985; Wed, 20 Mar 2019 07:51:52 -0700 (PDT) Date: Wed, 20 Mar 2019 15:51:17 +0100 In-Reply-To: Message-Id: <3faedcd2495a07e13b8611b2c63779d1d6d2b3f0.1553093421.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.225.g810b269d1ac-goog Subject: [PATCH v13 03/20] lib, arm64: untag user pointers in strn*_user 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 , Vincenzo Frascino , Eric Dumazet , "David S. Miller" , Alexei Starovoitov , Daniel Borkmann , Steven Rostedt , Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , Alex Deucher , "=?UTF-8?q?Christian=20K=C3=B6nig?=" , "David (ChunMing) Zhou" , Yishai Hadas , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, bpf@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, 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 , 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; -- 2.21.0.225.g810b269d1ac-goog