CVE-2026-53372 in Linux
Summary
by MITRE • 07/19/2026
In the Linux kernel, the following vulnerability has been resolved:
iommu/vt-d: Block PASID attachment to nested domain with dirty tracking
Kernel lacks dirty tracking support on nested domain attached to PASID, fails the attachment early if nesting parent domain is dirty tracking configured, otherwise dirty pages would be lost.
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Analysis
by VulDB Data Team • 07/19/2026
This vulnerability exists within the Linux kernel's IOMMU virtualization subsystem, specifically affecting the Intel Virtualization Technology for Directed I/O implementation. The flaw manifests when a nested domain configuration attempts to attach a Process Address Space ID (PASID) to a parent domain that has dirty page tracking enabled. This represents a critical design oversight in the memory management layer that governs virtualized I/O operations and memory isolation.
The technical root cause stems from insufficient validation within the IOMMU driver's domain attachment logic. When a guest operating system attempts to establish a PASID attachment to a nested virtual machine domain, the kernel fails to properly verify whether the parent domain has dirty tracking enabled. This creates a scenario where memory consistency mechanisms are bypassed, leading to potential data loss or corruption when dirty pages are not properly tracked across the virtualization boundary.
The operational impact of this vulnerability extends beyond simple memory management failures and can compromise the integrity of virtualized environments. In practical deployment scenarios, this flaw could allow malicious guest operating systems to manipulate memory tracking mechanisms, potentially enabling information disclosure or denial of service conditions. The vulnerability particularly affects systems utilizing Intel VT-d technology with nested virtualization capabilities, where multiple layers of memory isolation are present.
From a cybersecurity perspective, this vulnerability aligns with CWE-119 and CWE-787 categories related to improper access to memory and buffer overflows in virtualization contexts. It also relates to ATT&CK technique T1059 which involves executing malicious code within virtual environments, as attackers could exploit this weakness to manipulate memory tracking behaviors. The flaw essentially creates an attack surface where memory consistency guarantees are violated, potentially allowing for privilege escalation or data integrity compromise.
The mitigation strategy involves implementing early validation checks within the IOMMU subsystem to prevent PASID attachments to nested domains when their parent domains have dirty tracking configured. This requires updating the kernel's domain attachment logic to properly evaluate the compatibility of memory tracking configurations between parent and child domains, ensuring that incompatible configurations are rejected before any memory management operations occur.
Security administrators should prioritize patching affected systems and implementing monitoring for unauthorized virtualization configuration changes. The fix ensures that nested virtualization environments maintain proper memory consistency guarantees while preventing potential data loss scenarios. Organizations utilizing virtualized infrastructure with Intel VT-d capabilities must verify their systems are updated to prevent exploitation of this vulnerability which could lead to significant operational impacts in production environments.