CVE-2026-80696 in Linux
Summary
by MITRE • 08/28/2026
In the Linux kernel, the following vulnerability has been resolved:
hwmon: (ltc4282) Fix reading the minimum alarm voltage
Coverity reports an out-of-bounds access when reading the minimum alarm voltage for the VGPIO channel. Add the missing return statement to fix the problem.
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Analysis
by VulDB Data Team • 08/28/2026
The Linux kernel hardware monitoring subsystem, specifically within the ltc4282 driver responsible for managing Linear Technology LTC4282 power supply monitor chips, contained a critical logic error that resulted in an out-of-bounds memory access. This vulnerability was identified through static analysis tools such as Coverity and pertains to the retrieval of alarm voltage thresholds via the Virtual General Purpose Input/Output channel. The core technical flaw lies in the function responsible for reading the minimum alarm voltage, which failed to return a value under specific execution paths or conditions. In C programming within kernel space, functions that are expected to return integer values must explicitly handle all control flow branches with appropriate return statements. When this requirement is not met, particularly if the compiler does not issue warnings due to configuration settings or code structure, the function may proceed without returning a defined value. This leads to undefined behavior where the caller receives garbage data from registers or stack memory that was previously used for other operations.
The operational impact of this vulnerability extends beyond simple data corruption. Because the ltc4282 driver interacts directly with hardware sensors and exposes these values through sysfs interfaces, any process reading these attributes could receive invalid integer values representing voltage levels. In a worst-case scenario, if the garbage value is interpreted as an array index or used in subsequent arithmetic operations without validation, it could trigger further memory corruption issues. While the immediate manifestation might be incorrect sensor readings reported to system monitoring tools like lm-sensors, the underlying out-of-bounds access poses a risk of kernel instability. Depending on how the invalid data propagates through the stack and interacts with adjacent variables, this flaw could potentially lead to a denial of service by causing a kernel panic or oops, thereby disrupting system availability.
From a vulnerability classification perspective, this issue aligns with CWE-259, which covers use of hard-coded credentials if interpreted loosely as improper handling of expected values, but more accurately maps to CWE-787, out-of-bounds write access, or CWE-416, use after free, depending on the specific memory layout. However, given it is a read operation resulting from missing return logic leading to undefined behavior, it is most closely associated with CWE-252: Unchecked Return Value and CWE-908: Use of Uninitialized Resource. The lack of proper control flow management allows for unpredictable execution paths that compromise the integrity of system data. In terms of attack vectors, this vulnerability does not typically allow for direct remote code execution but represents a local privilege escalation risk if an unprivileged user can trigger specific hardware states to induce the faulty path and subsequently exploit the resulting memory state corruption.
Mitigation strategies primarily involve applying the upstream kernel patch that adds the missing return statement to ensure all code paths in the voltage reading function terminate correctly with valid data. System administrators should update their Linux kernels to versions where this fix is included, ensuring that the ltc4282 driver handles sensor queries robustly. For developers maintaining custom builds or out-of-tree modules, it is essential to enforce strict compiler warnings regarding missing return values using flags such as -Wreturn-missing in GCC and Clang. Additionally, integrating static analysis tools into the continuous integration pipeline can help detect similar logical errors before deployment. Regular auditing of hardware monitoring drivers for proper error handling and boundary checks remains a critical practice to maintain system stability and security integrity against potential exploitation through sensor data manipulation.