linux-kernel - RE: [PATCH 1/1] iommu/vt-d: Make context clearing consistent with context mapping

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]

Date:   Tue, 14 Nov 2023 03:20:08 +0000
From:   "Tian, Kevin" <kevin.tian@...el.com>
To:     Lu Baolu <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>
CC:     "iommu@...ts.linux.dev" <iommu@...ts.linux.dev>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH 1/1] iommu/vt-d: Make context clearing consistent with
 context mapping

> From: Lu Baolu <baolu.lu@...ux.intel.com>
> Sent: Tuesday, November 14, 2023 9:11 AM
> 
> In the iommu probe_device path, domain_context_mapping() allows setting
> up the context entry for a non-PCI device. However, in the iommu
> release_device path, domain_context_clear() only clears context entries
> for PCI devices.
> 
> Make domain_context_clear() behave consistently with
> domain_context_mapping() by clearing context entries for both PCI and
> non-PCI devices.
> 
> Fixes: 579305f75d34 ("iommu/vt-d: Update to use PCI DMA aliases")
> Signed-off-by: Lu Baolu <baolu.lu@...ux.intel.com>

The code before the fix tag also has the same problem. If we really want
backport then let's find out the very first commit which exhibits this
problem.

But I wonder the actual impact w/o such fix. If there is no hot-remove
possible for those non-PCI devices the context entry will be leaved
enabled until the machine is off. Then this fix is nice-to-have then
probably no need to backport?