CVE-2026-53019 in Linux
Summary
by MITRE • 06/24/2026
In the Linux kernel, the following vulnerability has been resolved:
clk: spacemit: ccu_mix: fix inverted condition in ccu_mix_trigger_fc()
Fix inverted condition that skips frequency change trigger, causing kernel panics during cpufreq scaling.
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Analysis
by VulDB Data Team • 06/25/2026
The vulnerability resides within the Linux kernel's clock management subsystem specifically affecting the spacemit platform clock controller implementation. This issue manifests in the ccu_mix_trigger_fc() function where an inverted conditional statement prevents proper frequency change triggering operations. The flaw occurs during cpu frequency scaling activities when the kernel attempts to modify clock frequencies dynamically based on system workload requirements. When the condition is inverted, the frequency change trigger mechanism fails to execute properly, resulting in kernel panics that disrupt system stability and potentially cause complete system crashes.
The technical root cause involves a logical error in the ccu_mix_trigger_fc() function where the conditional evaluation has been inverted, causing the system to skip critical frequency change operations. This type of condition inversion represents a classic software defect pattern that can be categorized under CWE-480 as using the wrong operator or incorrect boolean logic in conditional statements. The operational impact extends beyond simple performance degradation to complete system instability during scaling events, making this particularly dangerous in production environments where dynamic frequency scaling is essential for power management and thermal control.
During normal operation, the cpufreq subsystem relies on proper clock controller functionality to adjust processor frequencies according to workload demands. When the ccu_mix_trigger_fc() function fails due to the inverted condition, it prevents the kernel from properly communicating frequency change requests to the hardware clock controller. This creates a cascade effect where the system cannot maintain proper power states or thermal conditions, leading to kernel panics that require system rebooting and potentially data loss. The vulnerability affects systems utilizing the spacemit platform architecture where this specific clock controller implementation is deployed.
The mitigation strategy involves correcting the inverted conditional logic within the ccu_mix_trigger_fc() function to ensure proper frequency change triggering occurs during cpufreq scaling operations. This requires modifying the boolean condition evaluation to match the intended operational flow, allowing the clock controller to properly execute frequency changes when requested by the cpufreq subsystem. System administrators should apply the kernel patch that corrects this logic error, ensuring that frequency scaling operations proceed normally without triggering kernel panics. The fix aligns with standard security practices for maintaining system stability and preventing denial of service conditions during critical power management operations.
From an attack surface perspective, this vulnerability could potentially be exploited by malicious actors to cause system instability through forced frequency scaling operations, though the primary concern remains the legitimate kernel panic conditions that disrupt normal operation. The issue demonstrates the importance of thorough code review processes for critical kernel subsystems and highlights how seemingly minor logical errors can have significant operational impacts in embedded systems where power management is crucial for device functionality and user experience. This vulnerability type aligns with ATT&CK technique T1490 as it affects system stability and availability through kernel-level modifications.