linux-kernel - RE: [PATCH v4 09/10] iommu: Make iommu_queue

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: <BN9PR11MB52764790D53DF8AB4ED417098CF2A@BN9PR11MB5276.namprd11.prod.outlook.com>
Date:   Mon, 11 Sep 2023 06:57:31 +0000
From:   "Tian, Kevin" <kevin.tian@...el.com>
To:     Baolu Lu <baolu.lu@...ux.intel.com>,
        Joerg Roedel <joro@...tes.org>,
        "Will Deacon" <will@...nel.org>,
        Robin Murphy <robin.murphy@....com>,
        "Jason Gunthorpe" <jgg@...pe.ca>,
        Jean-Philippe Brucker <jean-philippe@...aro.org>,
        Nicolin Chen <nicolinc@...dia.com>
CC:     "Liu, Yi L" <yi.l.liu@...el.com>,
        Jacob Pan <jacob.jun.pan@...ux.intel.com>,
        "iommu@...ts.linux.dev" <iommu@...ts.linux.dev>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v4 09/10] iommu: Make iommu_queue_iopf() more generic

> From: Baolu Lu <baolu.lu@...ux.intel.com>
> Sent: Tuesday, September 5, 2023 1:24 PM
> 
> Hi Kevin,
> 
> I am trying to address this issue in below patch. Does it looks sane to
> you?
> 
> iommu: Consolidate per-device fault data management
> 
> The per-device fault data is a data structure that is used to store
> information about faults that occur on a device. This data is allocated
> when IOPF is enabled on the device and freed when IOPF is disabled. The
> data is used in the paths of iopf reporting, handling, responding, and
> draining.
> 
> The fault data is protected by two locks:
> 
> - dev->iommu->lock: This lock is used to protect the allocation and
>    freeing of the fault data.
> - dev->iommu->fault_parameter->lock: This lock is used to protect the
>    fault data itself.
> 
> Improve the iopf code to enforce this lock mechanism and add a reference
> counter in the fault data to avoid use-after-free issue.
> 

Can you elaborate the use-after-free issue and why a new user count
is required?

btw a Fix tag is required given this mislocking issue has been there for
quite some time...