CVE-2022-50776 in Linux
Summary
by MITRE • 12/24/2025
In the Linux kernel, the following vulnerability has been resolved:
clk: st: Fix memory leak in st_of_quadfs_setup()
If st_clk_register_quadfs_pll() fails, @lock should be freed before goto @err_exit, otherwise will cause meory leak issue, fix it.
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Analysis
by VulDB Data Team • 04/22/2026
The vulnerability identified as CVE-2022-50776 represents a memory leak issue within the Linux kernel's clock subsystem, specifically affecting the st_clk_register_quadfs_pll() function. This flaw resides in the clk-st driver which manages clock sources for certain embedded systems. The vulnerability occurs during the initialization process of quadfs PLL (Phase-Locked Loop) clock sources where proper resource cleanup is not performed when function execution fails. The issue demonstrates a classic memory management error that can lead to gradual resource exhaustion over time, particularly in systems that repeatedly attempt to register clock sources.
The technical flaw manifests in the st_of_quadfs_setup() function where the code path fails to properly release allocated memory resources when st_clk_register_quadfs_pll() returns an error condition. According to CWE-401, this constitutes a memory leak vulnerability where dynamically allocated memory is not freed before function exit, creating a resource consumption issue that can persist throughout system operation. The problem specifically occurs when the code follows a goto err_exit path without first freeing the @lock resource, which is allocated during the clock registration process. This represents a failure in proper error handling and resource management within kernel space code.
The operational impact of this vulnerability extends beyond simple memory consumption as it can lead to system instability and performance degradation over extended periods of operation. In embedded systems or devices with limited memory resources, this memory leak can eventually cause system crashes, reduced responsiveness, or complete system failure. The vulnerability affects systems using the st_clk_register_quadfs_pll() function for clock management, particularly those implementing quadfs PLL configurations. Attackers could potentially exploit this memory leak to cause denial of service conditions by repeatedly triggering the faulty code path, leading to progressive memory exhaustion. This aligns with ATT&CK technique T1499.004 for resource exhaustion attacks targeting memory resources.
Mitigation strategies for CVE-2022-50776 should focus on ensuring proper error handling and resource cleanup in kernel space code. The fix implemented in the Linux kernel requires that when st_clk_register_quadfs_pll() fails, the @lock resource must be freed before proceeding to the err_exit label. System administrators should ensure their kernels are updated to versions containing this fix, typically found in kernel releases from 5.19 onwards. Additionally, monitoring for memory usage patterns and implementing automated alerting for unusual memory consumption can help detect exploitation attempts. The fix demonstrates proper defensive programming practices that align with kernel security best practices, ensuring that all allocated resources are properly released regardless of execution path taken. Regular kernel updates and vulnerability scanning of embedded systems using affected clock drivers should be implemented as part of comprehensive security maintenance protocols.