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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 D91B2FC6196 for ; Fri, 8 Nov 2019 21:34:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5B81214DB for ; Fri, 8 Nov 2019 21:34:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="h8UmYkOx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731335AbfKHVeh (ORCPT ); Fri, 8 Nov 2019 16:34:37 -0500 Received: from mail-lj1-f196.google.com ([209.85.208.196]:42150 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726900AbfKHVeh (ORCPT ); Fri, 8 Nov 2019 16:34:37 -0500 Received: by mail-lj1-f196.google.com with SMTP id n5so7687209ljc.9 for ; Fri, 08 Nov 2019 13:34:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=iVwmfCxmYlGm1umF4hzbYjqVXwkqLwJV7uiys2HXotY=; b=h8UmYkOxKBDW3Ji9V8gSLC90Lv8INWtdO6eIMyWaEbmJgOD0SJSoeMJwPXAQXMDdqT IbWKWRJh2pq4hyni+m7rOZlkZywAZO8Z3oYJ3asRxgwVw1c56ba2G/6yEKGqmO/i9Wru ptpSN5TbYEy8FNkmOrk0k5aJBlF7Z51uFjpWGtcqY0obdT65eAwcYzCbhc6Xo0QkL/JY qRJlaLPyWBChT4tPx+FtUJSCd05EfMGWL+/+Dx5Lf74Wt9572ylmDALVWkGOYZ/XHvEh tuncA01p+elslmMXEQgxG/Ayt3heXvdpnpPe99GNea8+2ziQp4Au1LPpDWD4VdvQShw4 Oduw== 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:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=iVwmfCxmYlGm1umF4hzbYjqVXwkqLwJV7uiys2HXotY=; b=du3F503XHBVx9+em5YZIrg5B5nUflsztFbi4oSS1+IOMFpo8hqwC4cYvXQ3+LbkGs7 izhxlEBt7MtYJu2BLmE7CWzjVSZ3WJyYS8164sxYZ9ZrnqMhmEqZA7jZYIDFW5SbkNhc B4/JHZA6s4xuek2MnBPGUUfRXrUZspPXcANJ1/ViGsKvREOH6YVd8IIZKaZU/+XrjkgU i102oKRQE5ePesvQKIcdzbjvsRzsDnsJQOIJDWu0ld+gNEIemdF5rH0F0ttcLnsrfxz8 3G4FkveQPUSfMSrsZdzEaWN1cL5UsXP/gfWctD/iWMfoQuWv0E0OvEB87o3kC1DKicLQ 2c5w== X-Gm-Message-State: APjAAAVdyYWQ49xH4Bk6IyAycu2V6YMUyWfLJeCoDsDDZGeQHbxmJAd0 GMPJORPshxoP2vdBQRK28qub7Q== X-Google-Smtp-Source: APXvYqy+CScmrjFV80FpCyFPh+baJll0UA+hrc3T9V4VrDzeDL1dOUDtc/4aq/WcctTGXgHOOauF7g== X-Received: by 2002:a2e:8595:: with SMTP id b21mr2817240lji.155.1573248875254; Fri, 08 Nov 2019 13:34:35 -0800 (PST) Received: from cakuba ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id 68sm3530246ljf.26.2019.11.08.13.34.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Nov 2019 13:34:34 -0800 (PST) Date: Fri, 8 Nov 2019 13:34:28 -0800 From: Jakub Kicinski To: Jiri Pirko Cc: netdev@vger.kernel.org, davem@davemloft.net, idosch@mellanox.com, mlxsw@mellanox.com Subject: Re: [patch net-next] devlink: disallow reload operation during device cleanup Message-ID: <20191108133428.40f10fff@cakuba> In-Reply-To: <20191108204243.7241-1-jiri@resnulli.us> References: <20191108204243.7241-1-jiri@resnulli.us> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, 8 Nov 2019 21:42:43 +0100, Jiri Pirko wrote: > From: Jiri Pirko > > There is a race between driver code that does setup/cleanup of device > and devlink reload operation that in some drivers works with the same > code. Use after free could we easily obtained by running: > > while true; do > echo 10 > /sys/bus/netdevsim/new_device > devlink dev reload netdevsim/netdevsim10 & > echo 10 > /sys/bus/netdevsim/del_device > done > > Fix this by enabling reload only after setup of device is complete and > disabling it at the beginning of the cleanup process. > > Reported-by: Ido Schimmel > Fixes: 2d8dc5bbf4e7 ("devlink: Add support for reload") > Signed-off-by: Jiri Pirko I have no better ideas, so: Acked-by: Jakub Kicinski