CVE-2021-47140

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Source
https://cve.org/CVERecord?id=CVE-2021-47140
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47140.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2021-47140
Downstream
Published
2024-03-25T09:15:08.740Z
Modified
2026-03-14T14:59:04.726690Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved:

iommu/amd: Clear DMA ops when switching domain

Since commit 08a27c1c3ecf ("iommu: Add support to change default domain of an iommu group") a user can switch a device between IOMMU and direct DMA through sysfs. This doesn't work for AMD IOMMU at the moment because dev->dma_ops is not cleared when switching from a DMA to an identity IOMMU domain. The DMA layer thus attempts to use the dma-iommu ops on an identity domain, causing an oops:

# echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/unbind # echo identity > /sys/bus/pci/devices/0000:00:05.0/iommugroup/type # echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/bind ... BUG: kernel NULL pointer dereference, address: 0000000000000028 ... Call Trace: iommudmaalloc e1000esetuptxresources e1000e_open

Since iommuchangedevdefdomain() calls probefinalize() again, clear the dmaops there like Vt-d does.

References

Affected packages

Git /

Affected ranges

Database specific

unresolved_ranges 
[
    {
        "events": [
            {
                "introduced": "5.11"
            },
            {
                "fixed": "5.12.9"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "last_affected": "5.13-rc1"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "last_affected": "5.13-rc2"
            }
        ]
    },
    {
        "events": [
            {
                "introduced": "0"
            },
            {
                "last_affected": "5.13-rc3"
            }
        ]
    }
]
source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47140.json"