linux-kernel - Re: [PATCH v4 3/5] iommu/uapi: Use named union for user data

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <3b36c219-4120-402b-b03e-62b076db865c@linux.intel.com>
Date:   Wed, 8 Jul 2020 10:17:57 +0800
From:   Lu Baolu <baolu.lu@...ux.intel.com>
To:     Jacob Pan <jacob.jun.pan@...ux.intel.com>,
        iommu@...ts.linux-foundation.org,
        LKML <linux-kernel@...r.kernel.org>,
        Joerg Roedel <joro@...tes.org>,
        Alex Williamson <alex.williamson@...hat.com>
Cc:     baolu.lu@...ux.intel.com, David Woodhouse <dwmw2@...radead.org>,
        Yi Liu <yi.l.liu@...el.com>,
        "Tian, Kevin" <kevin.tian@...el.com>,
        Raj Ashok <ashok.raj@...el.com>,
        Christoph Hellwig <hch@...radead.org>,
        Jean-Philippe Brucker <jean-philippe@...aro.com>,
        Eric Auger <eric.auger@...hat.com>,
        Jonathan Corbet <corbet@....net>
Subject: Re: [PATCH v4 3/5] iommu/uapi: Use named union for user data

Hi Jacob,

On 7/8/20 7:43 AM, Jacob Pan wrote:
> IOMMU UAPI data size is filled by the user space which must be validated
> by ther kernel. To ensure backward compatibility, user data can only be
> extended by either re-purpose padding bytes or extend the variable sized
> union at the end. No size change is allowed before the union. Therefore,
> the minimum size is the offset of the union.
> 
> To use offsetof() on the union, we must make it named.
> 
> Link:https://lkml.org/lkml/2020/6/11/834

Please use lore.kernel.org links.

Best regards,
baolu