CVE-2024-56724 in Linux
Summary
by MITRE • 12/29/2024
In the Linux kernel, the following vulnerability has been resolved:
mfd: intel_soc_pmic_bxtwc: Use IRQ domain for TMU device
While design wise the idea of converting the driver to use the hierarchy of the IRQ chips is correct, the implementation has (inherited) flaws. This was unveiled when platform_get_irq() had started WARN() on IRQ 0 that is supposed to be a Linux IRQ number (also known as vIRQ).
Rework the driver to respect IRQ domain when creating each MFD device separately, as the domain is not the same for all of them.
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Analysis
by VulDB Data Team • 02/14/2026
The vulnerability CVE-2024-56724 affects the Linux kernel's management of interrupt handling within the intel_soc_pmic_bxtwc driver, which manages the thermal monitoring unit (TMU) device in Intel SoC platforms. This issue stems from improper implementation of IRQ domain handling during the driver's transition to use the hierarchical IRQ chip architecture. The root cause lies in how the driver manages interrupt resources when creating multiple MFD (Multi-Function Device) components, where each device requires specific IRQ domain contexts that are not properly maintained during the initialization process. The problem becomes apparent when platform_get_irq() function begins issuing warnings about IRQ 0, which should represent a valid Linux IRQ number or vIRQ, indicating a fundamental misalignment between the expected IRQ numbering scheme and the actual implementation.
The technical flaw manifests in the driver's failure to properly establish and maintain separate IRQ domains for each MFD device it creates, resulting in incorrect interrupt routing and potential system instability. When the driver attempts to initialize multiple MFD components, it inherits flawed logic that does not account for the fact that different devices within the same PMIC (Power Management Integrated Circuit) may require different IRQ domain contexts. This inheritance of improper interrupt handling mechanisms creates a scenario where the system may attempt to assign or reference IRQ numbers in ways that violate the expected Linux kernel interrupt subsystem conventions, particularly when dealing with the zero IRQ value that should be handled as a special case within the vIRQ framework.
The operational impact of this vulnerability extends beyond simple interrupt misconfiguration to potentially compromise system stability and security in embedded and mobile computing environments where Intel SoC platforms are prevalent. Systems utilizing affected kernels may experience unpredictable interrupt behavior, leading to potential denial of service conditions or incorrect thermal monitoring that could result in hardware overheating. The vulnerability affects the thermal management capabilities of devices, which could have cascading effects on system performance and reliability, particularly in scenarios where proper thermal monitoring is critical for hardware protection and system longevity. The issue particularly impacts devices running on Intel Broadwell and subsequent SoC platforms that utilize the intel_soc_pmic_bxtwc driver for power and thermal management functions.
Mitigation strategies for CVE-2024-56724 require immediate kernel updates that properly implement IRQ domain handling for each MFD device created by the intel_soc_pmic_bxtwc driver. The fix involves reworking the driver initialization process to ensure that each MFD component maintains its own distinct IRQ domain context rather than inheriting improper interrupt handling logic. This approach aligns with the established principles of kernel interrupt management and follows the recommended practices for MFD device driver development as outlined in the Linux kernel documentation. Organizations should prioritize applying the patched kernel version that resolves this issue, particularly in production environments where system stability and thermal management are critical. The solution also reinforces the importance of proper IRQ domain management in embedded systems, which is consistent with the security principles outlined in the CWE-248 category regarding "Uncaught Exception" and the ATT&CK framework's focus on system integrity and privilege escalation vectors. This vulnerability demonstrates the critical importance of maintaining proper interrupt routing in embedded systems and the potential security implications of improper resource management in kernel drivers.