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/iommu_group/type
# echo 0000:00:05.0 > /sys/sys/bus/pci/drivers/e1000e/bind
...
BUG: kernel NULL pointer dereference, address: 0000000000000028
...
Call Trace:
iommu_dma_alloc
e1000e_setup_tx_resources
e1000e_open

Since iommu_change_dev_def_domain() calls probe_finalize() again, clear
the dma_ops there like Vt-d does.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 19 Mar 2025 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel

Thu, 07 Nov 2024 17:15:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-05-04T07:04:55.158Z

Reserved: 2024-03-04T18:12:48.842Z

Link: CVE-2021-47140

cve-icon Vulnrichment

Updated: 2024-08-04T05:24:39.961Z

cve-icon NVD

Status : Analyzed

Published: 2024-03-25T09:15:08.740

Modified: 2025-03-19T16:28:16.000

Link: CVE-2021-47140

cve-icon Redhat

Severity : Low

Publid Date: 2024-03-25T00:00:00Z

Links: CVE-2021-47140 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses