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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 602DEC433E0 for ; Mon, 6 Jul 2020 21:40:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37BDE206B6 for ; Mon, 6 Jul 2020 21:40:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="X2zHDOTN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727055AbgGFVkQ (ORCPT ); Mon, 6 Jul 2020 17:40:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726001AbgGFVkQ (ORCPT ); Mon, 6 Jul 2020 17:40:16 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E99CC061755 for ; Mon, 6 Jul 2020 14:40:16 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id o1so9278028plk.1 for ; Mon, 06 Jul 2020 14:40:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=S8PPOwL6l2Qa5tBmuzCWfKqVL5UHTdEHxsmDd+xAnzM=; b=X2zHDOTNJJxY0s1N2WaVqaWAX0E1AoW926YUp/jqHRoHpZzkOUIHgynHDfFhLMl2bU cW5s9KB1H3iGKHCYccU+mRGbicmC4OLJPVHvTDnlQRbdH6xnHcGdyii296GtXoQfjYiU oQumYB9e9DRV0xxMwOOcLqZkTxpHB4PsHk9sw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=S8PPOwL6l2Qa5tBmuzCWfKqVL5UHTdEHxsmDd+xAnzM=; b=QdS8bWdLIyTvWSmHIwpY+Eaj6xTjfmGTKuuZfrS76koR+q6F4e4BvQtIJUyLGbwTqW q+atjhgEmw9L/nOHWZXNJx5KrAv3qe7jQg7v6CwXDgjsN33chLGvPmS9ypIlaKU6a8yq UzZvReuZ3ijcCFxZk2/NzdHsAhRsPrVwgleGQgenx6mGlKseclqCBN7v8CSe+FXUpSEm 88h9fHrDI/iNZywbl//9/GMibG4tJi3hxmpX/jJTyKAzA1UvsK35n4Y5VSsctZSo9qiG k/9z2esVVF+GkDedBVgj1yAm2QzOHwsZYTStQrk5N7da8vtmviYAgR0t1VeTH8Ke8PVq kWqg== X-Gm-Message-State: AOAM531CufR4wReIzeft9cbh0ma6SbO5pvoNvcpaghzQ6oXZl81Sqms/ FVNKhnY9FNPkDdvKT72quAdTFQ== X-Google-Smtp-Source: ABdhPJxfFUFYoO2RMHmnyzogkeoJ8sgrz7uvi6BJxPJY+5JXKtOGqopfD+gRzM7YUZ5yhTAs9xT5zQ== X-Received: by 2002:a17:902:b589:: with SMTP id a9mr6355094pls.98.1594071616026; Mon, 06 Jul 2020 14:40:16 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id q6sm20177080pfg.76.2020.07.06.14.40.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Jul 2020 14:40:14 -0700 (PDT) Date: Mon, 6 Jul 2020 14:40:13 -0700 From: Kees Cook To: Will Deacon Cc: Keno Fischer , Linux Kernel Mailing List , Oleg Nesterov , Andy Lutomirski , Will Drewry Subject: Re: ptrace: seccomp: Return value when the call was already invalid Message-ID: <202007061439.8BF61308@keescook> References: <20200703083914.GA18516@willie-the-truck> <202007030815.744AAB35D@keescook> <20200703154426.GA19406@willie-the-truck> <202007030851.D11F1EFA@keescook> <20200704123355.GA21185@willie-the-truck> <202007042132.DAFA2C2@keescook> <20200706081550.GA23032@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200706081550.GA23032@willie-the-truck> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 06, 2020 at 09:15:51AM +0100, Will Deacon wrote: > On Sat, Jul 04, 2020 at 09:56:50PM -0700, Kees Cook wrote: > > different per-architecture expectations). If I read this thread > > correctly, we need to test: > > > > syscall(-1), direct, returns ENOSYS > > syscall(-10), direct, returns ENOSYS > > syscall(-1), SECCOMP_RET_TRACE+PTRACE_CONT, returns ENOSYS > > syscall(-10), SECCOMP_RET_TRACE+PTRACE_CONT, returns ENOSYS > > syscall(-1), ptrace+PTRACE_SYSCALL, returns ENOSYS > > syscall(-10), ptrace+PTRACE_SYSCALL, returns ENOSYS > > > > do we need to double-check that registers before/after are otherwise > > unchanged too? (I *think* just looking at syscall return should be > > sufficient to catch the visible results.) > > There's also the case where the tracer sets the system call to -1 to skip > it. Yes, though that's already part of the seccomp selftests. (Specifically TRACE_syscall's syscall_faked.) -- Kees Cook