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=-16.4 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,URIBL_BLOCKED, 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 387FCC48BE9 for ; Mon, 24 Jun 2019 14:34:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08942208E4 for ; Mon, 24 Jun 2019 14:34:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="nl7WANT+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730215AbfFXOey (ORCPT ); Mon, 24 Jun 2019 10:34:54 -0400 Received: from mail-qk1-f201.google.com ([209.85.222.201]:57286 "EHLO mail-qk1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729020AbfFXOdO (ORCPT ); Mon, 24 Jun 2019 10:33:14 -0400 Received: by mail-qk1-f201.google.com with SMTP id j128so16247052qkd.23 for ; Mon, 24 Jun 2019 07:33:14 -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=QQXMFisLcqxTDxCx7mpHBfkykflxcDxM95yy0y46L4c=; b=nl7WANT+T3zzJdQNSfB9+m3b8ydqMfXiozgRLYeQCHFc4zWOn1Q8HlSZi7DGmunKcG m48YCubQKuyc5mIC9PWmc95WNcaYrn+rBkilmeEtWye/vcm/w7SgqxmZ+eLuRWNk+dBe ilcc0xwMAFdqkWVOavUtr03O5uEwSiv8ah8EA2ZNm/JYdo0vp1VaJuLVzssnLAaxlz0W +bGemSNE16fXrFDUhV0Eo7CJiC+zuIHkEvL14QgEfP6YhZ1zpRezDVdue+M4lC6Urd5x s/pZSUm/6UDNd/YlF2uYqWPTYuto+748pEjr815zYdNJlDljrtH9f8RpmzII6hCRLyFl B0aA== 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=QQXMFisLcqxTDxCx7mpHBfkykflxcDxM95yy0y46L4c=; b=HmYPPngry2IxzgJVdDWv+TvhUlVi+nE4SINIZc5Sp8hxsLFOKSneyLElnl86GgAsWz qJH4GbaHJzp3auQ8FaQlSibccYVPQNaRN//AxOgF2P5JGAJ6ONUoJ+NgsKyvHU9wGNU6 XZFKGYjllFHz2AYj8U6eD0kvWXp8HnUFhOI+sJBRMqM/j5vUHYt06imk9KttDX/7POWx 76Iz9sSEQUGoLUWo9WrUG63zClScj5TMxMFHShiSi4RlkBAdSrqL0iIwahtn6ZMM2F1d A8qLXgW+oy8oDUa89+jfLX9HTERO4iLUpqIwWhDVvhgu5pVRHBw978IM56VdRnMmdg5u EfhA== X-Gm-Message-State: APjAAAXv4SHj5AscrOD33y8+HlNDYpM2gUuyDwTf9gAOeUPXcD+/BXTv wHGflXONny3Jy7hoTMGQt/SfycIm7m2Q8zb+ X-Google-Smtp-Source: APXvYqzup51zNJearylpYQzBo2BoCcuJ3XXHspU9PtHQODnUVY/RZyP6CGJqukGO0YgO4GkOlCbGA2J//cHunZZU X-Received: by 2002:a37:a2cc:: with SMTP id l195mr16730110qke.362.1561386793770; Mon, 24 Jun 2019 07:33:13 -0700 (PDT) Date: Mon, 24 Jun 2019 16:32:48 +0200 In-Reply-To: Message-Id: <1a53da43d69d644793110e85671d20158ebf29cb.1561386715.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH v18 03/15] lib: 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 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: Vincenzo Frascino 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; -- 2.22.0.410.gd8fdbe21b5-goog