Linux Kernel IOMMU PASID State Reference Count Vulnerability

A vulnerability in the Linux kernel's IOMMU AMD driver has been addressed. The issue involved a race condition when unbinding the Process Address Space Identifier (PASID) state, which could lead to a reference count decrement warning and potential memory leak. This vulnerability was present in several versions of the Linux kernel.

Impact

The vulnerability could cause a reference count to incorrectly decrement to zero, leading to a memory leak warning.

Reproduction

The vulnerability can be reproduced by binding a PASID state, then unbinding it while there are outstanding page faults. This sequence triggers a race condition that causes the reference count to improperly decrement, generating a warning about leaking memory.

Remediation

Users can apply the latest patch available in the Linux kernel stable tree to address this vulnerability.