Received: by 2002:a05:6a10:1287:0:0:0:0 with SMTP id d7csp251918pxv; Thu, 15 Jul 2021 03:32:23 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxmdmktrX1lKwZbUV/hzfcTyJpKfUPyDnRHCIlyNMOzy7BU6uq/s4lssscjg6+fsPGFGlcb X-Received: by 2002:a02:a1c8:: with SMTP id o8mr3352365jah.50.1626345143122; Thu, 15 Jul 2021 03:32:23 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1626345143; cv=none; d=google.com; s=arc-20160816; b=ZErUbSmtbD/eaNEyi+1TumP8jSbNU4XbTVP4LRcp1+sUmUYvUzjxz0DXGM/ez5sffg /Puabd5PkPz17HvWBhOPybb8Q7k6NZqMYjvnzML1t+A57TXMOaK2cxHGuxSgwhDYBwnz ze/o+XAeaHUkiMzd11DmAl9eq74/RT/p6bqHwLO6VfYcC6SMgGhxN7qaVp9lmCxmgjdC 5qVODY61bOVeu75MpClVJoBUXUVlBzWrlRzHzPy9/tNO4M/KFf/jOKDufZeORWCxlbgi Odst1icKITnAnxt8QMFIJj6rrhw2awWslxUFUst982qa7Nz9R4ObpyRlhEOhazN4sRxl 1Nqg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date; bh=ooBvolgQ3qjJlu+4mgPZ8ZvB8Vvm1w5Ew474s4RErnE=; b=u7mhcR7GNhECB0kk31ePHiQ0nuezSSKxyhcnTF2M9yagH71yRHesOZfmM2eWCWK/N2 Pgp3fStwg4BDjAjvWUjOFZWdq4pECbWBiaMX/U3vE9GM0FkX+lJgZaOQgeVOomxNVi/U LCvhgmFoItH3ya3ZAqZm0CzIWCicURadxxBgyp9wKJtKJ1e0BmL/Sby8tVwsSCHq5To9 y1Mpn6CrYo7y7BpHotvtOMDWeWx2UT7s0yMkeg8CJgRQ4nrsDMvaXbdqhjfYwWoM7SyL ghJDh2NKC3SZh9rcsDTMPcBGw8RZu/POD9riV4jouX2VjEGdFTQaib2Thxh5TCZao2CC nckQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=8bytes.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id v15si6747319jas.5.2021.07.15.03.31.56; Thu, 15 Jul 2021 03:32:23 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=8bytes.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240320AbhGOHXD (ORCPT + 99 others); Thu, 15 Jul 2021 03:23:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240308AbhGOHXD (ORCPT ); Thu, 15 Jul 2021 03:23:03 -0400 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58A11C06175F for ; Thu, 15 Jul 2021 00:20:10 -0700 (PDT) Received: by theia.8bytes.org (Postfix, from userid 1000) id 5CE2B2C7; Thu, 15 Jul 2021 09:20:08 +0200 (CEST) Date: Thu, 15 Jul 2021 09:20:04 +0200 From: Joerg Roedel To: Frank Wunderlich Cc: iommu@lists.linux-foundation.org, Frank Wunderlich , Will Deacon , linux-kernel@vger.kernel.org, yong.wu@mediatek.com Subject: Re: [PATCH] iommu: check if group is NULL before remove device Message-ID: References: <20210715071150.82157-1-linux@fw-web.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210715071150.82157-1-linux@fw-web.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 15, 2021 at 09:11:50AM +0200, Frank Wunderlich wrote: > From: Frank Wunderlich > > if probe is failing, iommu_group may be not initialized, Sentences start with capital letters. IOMMU patch subjects too, after the 'iommu:' prefix. > so freeing it will result in NULL pointer access Please describe in more detail how this NULL-ptr dereference is triggered. Regards, Joerg