CVE-2022-48894: iommu/arm-smmu-v3: Don't unregister on shutdown

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-08-21 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: iommu/arm-smmu-v3: Don't unregister on shutdown Similar to SMMUv2, this driver calls iommu_device_unregister() from the shutdown path, which removes the IOMMU groups with no coordination whatsoever with their users - shutdown methods are optional in device drivers. This can lead to NULL pointer dereferences in those drivers' DMA API calls, or worse. Instead of calling the full arm_smmu_device_remove() from arm_smmu_device_shutdown(), let's pick only the relevant function call - arm_smmu_device_disable() - more or less the reverse of arm_smmu_device_reset() - and call just that from the shutdown path.

Affected products

Linux kernel: from 6.1 before 6.1.7; 6.2-rc1, 6.2-rc2, 6.2-rc3 — fixed in 6.1.7

How to fix

Upgrade to a fixed version: Linux kernel 6.1.7. Check the vendor advisory for mitigations.

References

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