CVE-2026-64171 in Linux
Summary
by MITRE • 07/19/2026
In the Linux kernel, the following vulnerability has been resolved:
i2c: tegra: fix pm_runtime leak on mutex_lock failure
If tegra_i2c_mutex_lock() fails, the function returns without calling pm_runtime_put(), leaking the runtime PM reference acquired by the preceding pm_runtime_get_sync(). This prevents the device from ever entering runtime suspend.
Add the missing pm_runtime_put() before returning on lock failure.
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Analysis
by VulDB Data Team • 07/20/2026
This vulnerability resides within the linux kernel's i2c tegra driver where a runtime power management reference leak occurs during mutex locking operations. The issue specifically affects the tegra_i2c_mutex_lock() function which handles synchronization for i2c communication on tegra platform devices. When this function encounters a failure during mutex locking, it prematurely returns without properly releasing the runtime power management reference that was previously acquired through pm_runtime_get_sync(). This creates a resource leak condition that prevents the device from entering its intended runtime suspend state, thereby maintaining unnecessary power consumption and potentially impacting system efficiency.
The technical flaw represents a classic resource management error where proper cleanup operations are omitted upon function failure paths. According to CWE-459, this vulnerability falls under incomplete cleanup scenarios where acquired resources are not properly released when control flow exits a function prematurely. The mutex locking mechanism in the tegra i2c driver acquires a runtime power management reference to ensure the device remains active during i2c operations, but fails to release this reference when the locking operation itself fails. This creates a persistent hold on the device's power state that cannot be resolved until the system reboots or the device is manually reset.
The operational impact of this vulnerability extends beyond simple power consumption concerns to potentially affect system stability and battery life in mobile devices. When runtime power management is compromised, the affected i2c devices remain active longer than necessary, consuming additional power and potentially causing thermal issues on battery-powered systems. In embedded systems where power efficiency is critical, this leak can contribute to reduced battery life and increased heat generation. The vulnerability affects all systems running linux kernels with the tegra i2c driver where i2c operations might fail during mutex acquisition, creating a persistent condition that prevents proper device power state transitions.
Mitigation strategies focus on implementing proper error handling within the mutex locking function to ensure resource cleanup occurs regardless of execution path. The fix involves adding the missing pm_runtime_put() call before returning from tegra_i2c_mutex_lock() when lock failure occurs, ensuring that the runtime power management reference is properly released even in error conditions. This follows established security practices outlined in the linux kernel coding standards and ATT&CK technique T1547.006 for privilege escalation through resource exhaustion or improper cleanup. System administrators should update to patched kernel versions that implement this fix, while developers should review similar patterns in other device drivers to prevent analogous resource leaks. The vulnerability demonstrates the importance of maintaining proper resource accounting in concurrent programming scenarios where multiple synchronization mechanisms interact with power management subsystems.