CVE-2021-47327 iommu/arm-smmu: Fix arm_smmu_device refcount leak when arm_smmu_rpm_get fails

2024-05-2114:35:39

Linux

github.com

linux

kernel

vulnerability

arm_smmu_device

refcount

leak

fix

iommu arm-smmu

pm_runtime_get_sync

pm_runtime_resume_and_get

AI Score

6.7

Confidence

Low

EPSS

Percentile

15.5%

SSVC

Exploitation

none

Automatable

Technical Impact

partial

JSON

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

iommu/arm-smmu: Fix arm_smmu_device refcount leak when arm_smmu_rpm_get fails

arm_smmu_rpm_get() invokes pm_runtime_get_sync(), which increases the
refcount of the “smmu” even though the return value is less than 0.

The reference counting issue happens in some error handling paths of
arm_smmu_rpm_get() in its caller functions. When arm_smmu_rpm_get()
fails, the caller functions forget to decrease the refcount of “smmu”
increased by arm_smmu_rpm_get(), causing a refcount leak.

Fix this issue by calling pm_runtime_resume_and_get() instead of
pm_runtime_get_sync() in arm_smmu_rpm_get(), which can keep the refcount
balanced in case of failure.

ADP Affected

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    "defaultStatus": "unknown"
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