CVE-2026-72295 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: KVM: Validate irqchip index in irqfd routing
Sashiko reported that the irqchip index is not validated for LoongArch. Add validation and reject out-of-range irqchip indexes to avoid indexing past the routing table's chip array.
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Analysis
by VulDB Data Team • 08/15/2026
The vulnerability identified in the Linux kernel affects the LoongArch architecture within the Kernel-based Virtual Machine implementation, specifically concerning interrupt handling mechanisms. This issue resides in the irqfd routing functionality where the system fails to properly validate irqchip indices during virtual interrupt processing. The flaw represents a classic buffer over-read condition that could potentially allow malicious actors to exploit memory access violations through improper index validation.
The technical implementation defect occurs within the KVM subsystem when processing interrupt requests for LoongArch virtual machines. Without proper bounds checking on irqchip indices, the system may attempt to access memory locations beyond the allocated routing table chip array boundaries. This validation gap creates an opportunity for attackers to craft malformed interrupt requests that could trigger unauthorized memory access patterns, potentially leading to information disclosure or system instability.
From an operational perspective, this vulnerability presents significant security implications for virtualized environments running on LoongArch hardware. The attack surface expands when considering that KVM virtual machines rely on proper interrupt routing for communication between guest operating systems and host hardware resources. An attacker with access to the virtual machine environment could exploit this flaw to bypass memory protection mechanisms, potentially escalating privileges or causing denial of service conditions within the virtualized infrastructure.
The vulnerability aligns with CWE-129, which addresses improper validation of array indices, and specifically relates to improper input validation in kernel space code. This weakness can be mapped to ATT&CK technique T1068, which covers "Exploitation for Privilege Escalation" through kernel exploits, as the flawed validation could enable attackers to manipulate memory access patterns within kernel space. The fix implements proper range checking that ensures irqchip indices remain within acceptable bounds before accessing the routing table structures.
Mitigation strategies should focus on immediate patch deployment across all affected LoongArch systems running KVM virtualization environments. System administrators must verify that their virtual machine configurations properly validate interrupt routing parameters and monitor for anomalous interrupt handling patterns. Additionally, implementing runtime integrity checks for irqchip indices can provide additional defense layers against potential exploitation attempts. The fix demonstrates the importance of proper input validation in kernel space code, particularly when dealing with hardware-specific virtualization features that require precise memory management and access control mechanisms.
The resolution addresses fundamental security principles by ensuring proper bounds checking before array access operations, preventing unauthorized memory traversal through validated index ranges. This implementation reinforces secure coding practices recommended for kernel development environments where resource access must be strictly controlled to maintain system integrity and prevent privilege escalation attacks.