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 9E22BC4360F for ; Mon, 18 Mar 2019 17:19:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6E76421473 for ; Mon, 18 Mar 2019 17:19:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="oz1fvLMf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727827AbfCRRSA (ORCPT ); Mon, 18 Mar 2019 13:18:00 -0400 Received: from mail-io1-f73.google.com ([209.85.166.73]:53099 "EHLO mail-io1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727812AbfCRRR7 (ORCPT ); Mon, 18 Mar 2019 13:17:59 -0400 Received: by mail-io1-f73.google.com with SMTP id p143so14206166iod.19 for ; Mon, 18 Mar 2019 10:17:58 -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=oz1fvLMfcGfF81Olx8UNQHEZSNueq6Qn8HIXigOddOJDAD2tg4UjJfuFuQZjoILWrg CZQbFlcBOVlSuoBIyl+jHf6+DdY1aYxqiZ+PbKmfk+lr5pHfcoSSl29R6PrgmkRv2+Vt jaBUYlq/IjUpt3LjnPub3yHlYsiou77HiwqH/RPJgcNyMlQiwfZhgtvbqZ2qkfe+w8YV JszqgrO+qE+QbtWQuzywwpj8p6QWhPyanRNQsRRsaA1VHxFYfquhluxhBFXc65JKlppp Ta4otXITXmaoRx/+KSZjVysEXe12wNPaDhCUR3L2hY/+Bjcp+T9no9YB/s9yH1290+KX DWGw== 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=BzRuYb/9q3Z8v7XXLVreiIc05fOEkOXz1JJXRgpN/hP9gH8A4Ydp1rdhCxSDPqAi4t A6jlOWp/Iw3gIQcpzCdyCLnCBIiDVU7ghbMw78cVBZU5SNinrjImA7m3mfnKV0Z0Sqrt y2yRCBsHPIa7jNdewQJ+3rLz0n3YFCaLCgqzNSnYOV3S+bD/PODhgLsQhU+4Hbv5GgX+ n6xo+rUuMZNafeq9mEjD0RQZhG+m2XtZxaRvDJyLA3asWyUZxrWMz01fu9ak2ru6Q0Cl ZbHFbtYuEIER1pgV/A7Iy5d0mMKQZ1LyHWcEuPNLcYLYqjAEievFwCJ8cy7shbXR3RP0 +zwA== X-Gm-Message-State: APjAAAUnLkmO4lSeQhiM1DONYdX/SbgY61ySn3QR8ab8qTEB4CO7+QHy grqQSOii39tGJNPJS0jKBCqJWVHhGtJsfaqn X-Google-Smtp-Source: APXvYqzY2/zsv7O6GF0gVVMoQ0dZ1/muXN5k1+3Ljt96vcewESoCRYK8ve5Pym7TRNy6ing4+VelgBsDa+oWzLVC X-Received: by 2002:a24:29c5:: with SMTP id p188mr10832598itp.4.1552929478230; Mon, 18 Mar 2019 10:17:58 -0700 (PDT) Date: Mon, 18 Mar 2019 18:17:35 +0100 In-Reply-To: Message-Id: Mime-Version: 1.0 References: X-Mailer: git-send-email 2.21.0.225.g810b269d1ac-goog Subject: [PATCH v12 03/13] 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 , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, netdev@vger.kernel.org, bpf@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: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@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