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=-16.3 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_HELO_NONE,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 8292CC31E47 for ; Wed, 12 Jun 2019 11:43:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5650B208C2 for ; Wed, 12 Jun 2019 11:43:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="wWQdCeaE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2409104AbfFLLnq (ORCPT ); Wed, 12 Jun 2019 07:43:46 -0400 Received: from mail-oi1-f201.google.com ([209.85.167.201]:56513 "EHLO mail-oi1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2409095AbfFLLnn (ORCPT ); Wed, 12 Jun 2019 07:43:43 -0400 Received: by mail-oi1-f201.google.com with SMTP id u200so5306162oia.23 for ; Wed, 12 Jun 2019 04:43:43 -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=UjHW3gvZNVNgT5aLmmsHnPxo+B7J7BC6tuQvc/RhPNk=; b=wWQdCeaEB2u6K2FokoVH57TiuY9+YM+iloWJZ9olfqp0zjmIdmC5f6DPCzUKmsxGdy S65EVOJIDT5V4zwCQfqNTJzphOcFWfUmY+gXBOeFncv77kXLYdKYGCkdMxc+OyweaWX0 0fKTo4iZRRAvEu0L5K9N5O0E1jscX+Pk92PzQ1PknQ2YOc6xMrIj1RN7n/IEUROoLRHK DSyTNlm/Sr+vicrs5WJhiUx/1nLhQ5Q4ACjS55YPvH7eOOqFTP/CfYXsftMzptdGowR3 ikQ6jhRMQBxQ3FPli1xBTZa23yNKdUvKN2sR5HTTLiPeqs1dY61XYlyLOGrjNBMaj6hd 3iow== 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=UjHW3gvZNVNgT5aLmmsHnPxo+B7J7BC6tuQvc/RhPNk=; b=OPxavJLQE5WVfNLJz/7m583/JWaYmL0n11kfOnVWPNdGtI+5QDJ7yijVYzi9W/fRDV OPzEJtEm+m547Fu0B6HXUJS8xFCs4M+mrnCrop05P+zupaSOjLv4bDdqFafR+TB60uCe itRpjlvc+gStTKriYzefnKnS+Y6nwdomF07rXZWfMbqCrEEer/Ude9WflwOfe9TNPl2w NUq1DAY43Fh5eFMZnG47Sy4N6ZHjBRs74WcG1MsmZploYhc6LosjxZXZI89FKzotugRe O0UClxiUBeA1j/lWVxfzZQVMVGitUYPlArnPcQ1nTMxgWOrksFKDMfmnnwqAQWt8ze8Z 5/9Q== X-Gm-Message-State: APjAAAVsoiVnPeA/UceyJQYW/LbyMw6wbvEu1Yic13hADEQAm/LuNUBE aWhy9mO4we50mXi4YsArYDyawe7UiBJroSnF X-Google-Smtp-Source: APXvYqwN3f56c3YdzV4vuBZtnTaXMq2rkbV7EZJhl+9vuDir+VdtrZMmSzDSSPuiOLJaxWwDb81r7VAwTgFT1eUN X-Received: by 2002:a9d:764d:: with SMTP id o13mr6499138otl.298.1560339823090; Wed, 12 Jun 2019 04:43:43 -0700 (PDT) Date: Wed, 12 Jun 2019 13:43:19 +0200 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.22.0.rc2.383.gf4fbbf30c2-goog Subject: [PATCH v17 02/15] 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 , Felix Kuehling , Alexander Deucher , Christian Koenig , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Luc Van Oostenryck , Dave Martin , Khalid Aziz , enh , Jason Gunthorpe , Christoph Hellwig , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , 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. Reviewed-by: Khalid Aziz Acked-by: Kees Cook Reviewed-by: Catalin Marinas 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 023ba9f3b99f..dccb95af6003 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -6,6 +6,7 @@ #include #include #include +#include #include #include @@ -108,7 +109,7 @@ 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 7f2db3fe311f..28ff554a1be8 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; -- 2.22.0.rc2.383.gf4fbbf30c2-goog