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

iommu/amd/iommu_v2: Fix pasid_state refcount dec hit 0 warning on pasid unbind

When unbinding pasid - a race condition exists vs outstanding page faults.

To prevent this, the pasid_state object contains a refcount.
* set to 1 on pasid bind
* incremented on each ppr notification start
* decremented on each ppr notification done
* decremented on pasid unbind

Since refcount_dec assumes that refcount will never reach 0:
the current implementation causes the following to be invoked on
pasid unbind:
REFCOUNT_WARN("decrement hit 0; leaking memory")

Fix this issue by changing refcount_dec to refcount_dec_and_test
to explicitly handle refcount=1.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 02 Oct 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low


Wed, 01 Oct 2025 12:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: iommu/amd/iommu_v2: Fix pasid_state refcount dec hit 0 warning on pasid unbind When unbinding pasid - a race condition exists vs outstanding page faults. To prevent this, the pasid_state object contains a refcount. * set to 1 on pasid bind * incremented on each ppr notification start * decremented on each ppr notification done * decremented on pasid unbind Since refcount_dec assumes that refcount will never reach 0: the current implementation causes the following to be invoked on pasid unbind: REFCOUNT_WARN("decrement hit 0; leaking memory") Fix this issue by changing refcount_dec to refcount_dec_and_test to explicitly handle refcount=1.
Title iommu/amd/iommu_v2: Fix pasid_state refcount dec hit 0 warning on pasid unbind
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-10-01T11:45:52.204Z

Reserved: 2025-10-01T11:39:39.404Z

Link: CVE-2023-53501

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-10-01T12:15:53.640

Modified: 2025-10-01T12:15:53.640

Link: CVE-2023-53501

cve-icon Redhat

Severity : Low

Publid Date: 2025-10-01T00:00:00Z

Links: CVE-2023-53501 - Bugzilla

cve-icon OpenCVE Enrichment

No data.