Vulnerability Details : CVE-2021-47140
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.
Vulnerability category: Memory Corruption
Products affected by CVE-2021-47140
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Exploit prediction scoring system (EPSS) score for CVE-2021-47140
0.04%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 9 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-47140
Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
---|---|---|---|---|---|---|
5.3
|
MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
3.9
|
1.4
|
134c704f-9b21-4f2e-91b3-4a467353bcc0 | 2024-11-07 |
5.5
|
MEDIUM | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
N/A
|
N/A
|
RedHat-CVE-2021-47140 | 2024-03-25 |
References for CVE-2021-47140
-
https://git.kernel.org/stable/c/f3f2cf46291a693eab21adb94171b0128c2a9ec1
iommu/amd: Clear DMA ops when switching domain - kernel/git/stable/linux.git - Linux kernel stable tree
-
https://git.kernel.org/stable/c/d6177a6556f853785867e2ec6d5b7f4906f0d809
iommu/amd: Clear DMA ops when switching domain - kernel/git/stable/linux.git - Linux kernel stable tree
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