Linux Kernel Buffer Overflow in iommufd Event Queue

CVE-2026-64293 is a buffer overflow vulnerability in the Linux kernel's iommufd (IOMMU File Descriptor) subsystem, specifically in the virtual event queue read operation. The flaw stems from a sizeof() operator misuse where sizeof(hdr) returns the size of a pointer rather than the actual structure, causing inadequate bounds checking. This allows an attacker with access to iommufd operations to write beyond allocated buffer boundaries, potentially leading to kernel memory corruption, privilege escalation, or denial of service. Systems running vulnerable Linux kernels with iommufd enabled are affected, particularly those relying on IOMMU virtualization for nested guest support or device passthrough scenarios.

Casky.ai's Claude-powered analysis engine would detect attack patterns associated with this vulnerability by identifying memory manipulation techniques mapped to MITRE ATT&CK's Execution and Privilege Escalation tactics. Practitioners using Casky would see findings related to improper input validation (CWE-119 class), suspicious kernel memory access patterns, and potential exploitation chains leveraging T1548 (Abuse Elevation Control Mechanism) or T1611 (Escape to Host) if containerized. The platform's 754 security skills would flag suspicious iommufd syscall sequences, abnormal buffer operations, and attempts to trigger the sizeof() logic error—enabling defenders to identify exploitation attempts before kernel compromise occurs.