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.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00047.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Linux Linux unaffected
Version Status Constraints
d4a44f0750bb9bf7c44c22444a482756b2344a79 affected < 3761ae0d0e549f2acdaf11f49df4ed06d256b20f
d4a44f0750bb9bf7c44c22444a482756b2344a79 affected < c4007596fbdabc29f858dc2e1990858a146b60b2
d4a44f0750bb9bf7c44c22444a482756b2344a79 affected < fbf4daa6f4105e01fbd3868006f65c163365c1e3
d4a44f0750bb9bf7c44c22444a482756b2344a79 affected < fe92c058199067ae90cf2a901ddf3c271893557a
d4a44f0750bb9bf7c44c22444a482756b2344a79 affected < 1adf30f198c26539a62d761e45af72cde570413d
Linux Linux affected
Version Status Constraints
5.0 affected —
0 unaffected < 5.0
5.4.134 unaffected ≤ 5.4.*
5.10.52 unaffected ≤ 5.10.*
5.12.19 unaffected ≤ 5.12.*
5.13.4 unaffected ≤ 5.13.*
5.14 unaffected ≤ *

Configuration 1 [-]

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

No data.

No data.

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/1adf30f198c26539a62d761e45af72cde570413d cve-icon cve-icon
https://git.kernel.org/stable/c/3761ae0d0e549f2acdaf11f49df4ed06d256b20f cve-icon cve-icon
https://git.kernel.org/stable/c/c4007596fbdabc29f858dc2e1990858a146b60b2 cve-icon cve-icon
https://git.kernel.org/stable/c/fbf4daa6f4105e01fbd3868006f65c163365c1e3 cve-icon cve-icon
https://git.kernel.org/stable/c/fe92c058199067ae90cf2a901ddf3c271893557a cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2024052133-CVE-2021-47327-bbe1@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2021-47327 cve-icon
https://www.cve.org/CVERecord?id=CVE-2021-47327 cve-icon
History

Tue, 09 Dec 2025 22:15:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 02 Apr 2025 15:00:00 +0000

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

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-12-18T11:36:47.214Z

Reserved: 2024-05-21T14:28:16.975Z

Link: CVE-2021-47327

cve-icon Vulnrichment

Updated: 2024-08-04T05:32:08.559Z

cve-icon NVD

Status : Analyzed

Published: 2024-05-21T15:15:19.757

Modified: 2025-04-02T14:33:00.990

Link: CVE-2021-47327

cve-icon Redhat

Severity : Low

Publid Date: 2024-05-21T00:00:00Z

Links: CVE-2021-47327 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses