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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 5DE1BC433E0 for ; Tue, 21 Jul 2020 05:35:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 40EA720792 for ; Tue, 21 Jul 2020 05:35:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728068AbgGUFfq (ORCPT ); Tue, 21 Jul 2020 01:35:46 -0400 Received: from verein.lst.de ([213.95.11.211]:50620 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725774AbgGUFfq (ORCPT ); Tue, 21 Jul 2020 01:35:46 -0400 Received: by verein.lst.de (Postfix, from userid 2407) id 78C446736F; Tue, 21 Jul 2020 07:35:42 +0200 (CEST) Date: Tue, 21 Jul 2020 07:35:42 +0200 From: Christoph Hellwig To: Guenter Roeck Cc: Christoph Hellwig , Nick Hu , Greentime Hu , Vincent Chen , Paul Walmsley , Palmer Dabbelt , Andrew Morton , Linus Torvalds , linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/6] syscalls: use uaccess_kernel in addr_limit_user_check Message-ID: <20200721053542.GA10301@lst.de> References: <20200714105505.935079-1-hch@lst.de> <20200714105505.935079-2-hch@lst.de> <20200718013849.GA157764@roeck-us.net> <20200718094846.GA8593@lst.de> <20200720221046.GA86726@roeck-us.net> <20200721045834.GA9613@lst.de> <20200721052022.GA10011@lst.de> <7fc565fe-411e-6a0b-8aaf-0bf808f0d6a9@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <7fc565fe-411e-6a0b-8aaf-0bf808f0d6a9@roeck-us.net> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 20, 2020 at 10:30:30PM -0700, Guenter Roeck wrote: > Guess I lost it somewhere. Are you saying the check was wrong all along > and your patch fixed it ? Oh, it is a little complicated. Normally we have two address space limits, KERNEL_DS and USER_DS, and they are supposed to be different. armnommu and m68k define them to the same value for no good reason. That leads to: uaccess_kernel always returning true as it does a positive check agains KERNEL_DS, which disables a bunch of drivers like sg and rdma, and could also lead to really strange and probably broken results in a few places. It also leads to the SIGKILL in addr_limit_user_check never triggering due to the negatŃ–ve check, which is ok as the limits never are different. 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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 23022C433E2 for ; Tue, 21 Jul 2020 05:36:00 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DE02820792 for ; Tue, 21 Jul 2020 05:35:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="vaIEGmnY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE02820792 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=nGhDwcgSQ5EfhvLOHebtO6QvJbfYJsajrcxsibfI7Bc=; b=vaIEGmnYSACrGZr2Z831wkPdP E7pyomZ8Miw/ahmXTcUx1rDIJT+zQfAnBmnH3A6qCKZhRxXU1vp0FMCrTbJwJ9eJ4jwyvtC2n4WYk G1kFO+ZhmxUYyy2oCarXm7DAlJAVwlLbxiq2KSFhEroOJcNz3cX6DH7uskrB1ZF4JaDLHAr/r8FCR 8sREc0NmVv0CG/sYZC5b2ThghZlzOR6ChEal1LzgzdZcOeADE5Uz9pGY3LI8bTY7UbyNhBJ81Cdut wqvl8ZETjv7RYBhwSqmzW9CdVR5wEMnvNTiZRbcOxAeBYZVw+Z+HqqU8HODK6gRQZwQXW8a8JgiTU zlljny1TA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jxkwN-00046z-DU; Tue, 21 Jul 2020 05:35:47 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jxkwL-00046Y-1u for linux-riscv@lists.infradead.org; Tue, 21 Jul 2020 05:35:46 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 78C446736F; Tue, 21 Jul 2020 07:35:42 +0200 (CEST) Date: Tue, 21 Jul 2020 07:35:42 +0200 From: Christoph Hellwig To: Guenter Roeck Subject: Re: [PATCH 1/6] syscalls: use uaccess_kernel in addr_limit_user_check Message-ID: <20200721053542.GA10301@lst.de> References: <20200714105505.935079-1-hch@lst.de> <20200714105505.935079-2-hch@lst.de> <20200718013849.GA157764@roeck-us.net> <20200718094846.GA8593@lst.de> <20200720221046.GA86726@roeck-us.net> <20200721045834.GA9613@lst.de> <20200721052022.GA10011@lst.de> <7fc565fe-411e-6a0b-8aaf-0bf808f0d6a9@roeck-us.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <7fc565fe-411e-6a0b-8aaf-0bf808f0d6a9@roeck-us.net> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200721_013545_230851_CE004CD9 X-CRM114-Status: UNSURE ( 9.81 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Nick Hu , linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, Palmer Dabbelt , Greentime Hu , Paul Walmsley , Andrew Morton , Vincent Chen , Linus Torvalds , Christoph Hellwig Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org T24gTW9uLCBKdWwgMjAsIDIwMjAgYXQgMTA6MzA6MzBQTSAtMDcwMCwgR3VlbnRlciBSb2VjayB3 cm90ZToKPiBHdWVzcyBJIGxvc3QgaXQgc29tZXdoZXJlLiBBcmUgeW91IHNheWluZyB0aGUgY2hl Y2sgd2FzIHdyb25nIGFsbCBhbG9uZwo+IGFuZCB5b3VyIHBhdGNoIGZpeGVkIGl0ID8KCk9oLCBp dCBpcyBhIGxpdHRsZSBjb21wbGljYXRlZC4KCk5vcm1hbGx5IHdlIGhhdmUgdHdvIGFkZHJlc3Mg c3BhY2UgbGltaXRzLCBLRVJORUxfRFMgYW5kIFVTRVJfRFMsCmFuZCB0aGV5IGFyZSBzdXBwb3Nl ZCB0byBiZSBkaWZmZXJlbnQuICBhcm1ub21tdSBhbmQgbTY4ayBkZWZpbmUgdGhlbQp0byB0aGUg c2FtZSB2YWx1ZSBmb3Igbm8gZ29vZCByZWFzb24uICBUaGF0IGxlYWRzIHRvOgoKdWFjY2Vzc19r ZXJuZWwgYWx3YXlzIHJldHVybmluZyB0cnVlIGFzIGl0IGRvZXMgYSBwb3NpdGl2ZSBjaGVjawph Z2FpbnMgS0VSTkVMX0RTLCB3aGljaCBkaXNhYmxlcyBhIGJ1bmNoIG9mIGRyaXZlcnMgbGlrZSBz ZyBhbmQKcmRtYSwgYW5kIGNvdWxkIGFsc28gbGVhZCB0byByZWFsbHkgc3RyYW5nZSBhbmQgcHJv YmFibHkgYnJva2VuCnJlc3VsdHMgaW4gYSBmZXcgcGxhY2VzLgoKSXQgYWxzbyBsZWFkcyB0byB0 aGUgU0lHS0lMTCBpbiBhZGRyX2xpbWl0X3VzZXJfY2hlY2sgbmV2ZXIKdHJpZ2dlcmluZyBkdWUg dG8gdGhlIG5lZ2F00ZZ2ZSBjaGVjaywgd2hpY2ggaXMgb2sgYXMgdGhlIGxpbWl0cwpuZXZlciBh cmUgZGlmZmVyZW50LgoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX18KbGludXgtcmlzY3YgbWFpbGluZyBsaXN0CmxpbnV4LXJpc2N2QGxpc3RzLmluZnJhZGVh ZC5vcmcKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1y aXNjdgo=