CVE-2023-53807 in Linux
Summary
by MITRE • 12/09/2025
In the Linux kernel, the following vulnerability has been resolved:
clk: clocking-wizard: Fix Oops in clk_wzrd_register_divider()
Smatch detected this potential error pointer dereference clk_wzrd_register_divider(). If devm_clk_hw_register() fails then it sets "hw" to an error pointer and then dereferences it on the next line. Return the error directly instead.
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Analysis
by VulDB Data Team • 03/29/2026
The vulnerability identified as CVE-2023-53807 resides within the Linux kernel's clocking-wizard subsystem, specifically affecting the clk_wzrd_register_divider() function. This issue represents a classic null pointer dereference scenario that could lead to system instability and potential denial of service conditions. The flaw manifests when the devm_clk_hw_register() function encounters an error during hardware clock registration, causing it to return an error pointer instead of a valid hardware clock handle. The subsequent code path fails to properly handle this error condition, resulting in an attempt to dereference the error pointer which ultimately triggers a kernel oops and system crash.
The technical implementation of this vulnerability stems from improper error handling within the clocking-wizard driver code. When devm_clk_hw_register() fails to register a hardware clock component, it returns an error pointer through the standard Linux kernel error handling mechanism. However, the clk_wzrd_register_divider() function does not check for this error condition before proceeding to use the returned value. This pattern directly violates established kernel coding practices and represents a fundamental flaw in defensive programming. The Smatch static analysis tool identified this issue by detecting the potential for dereferencing an error pointer that could have been returned from the devm_clk_hw_register() call, which is a common anti-pattern in kernel development.
The operational impact of CVE-2023-53807 extends beyond simple system crashes, potentially affecting embedded systems and devices that rely heavily on precise clock management for their operation. Systems utilizing the clocking-wizard framework, particularly those in industrial control, automotive applications, or network infrastructure equipment, could experience unexpected system failures when attempting to register clock dividers. This vulnerability affects the broader Linux kernel ecosystem, as it impacts the stability of clock management subsystems that are fundamental to system timing and synchronization. The issue could be exploited by malicious actors to cause persistent denial of service conditions, particularly in environments where clock stability is critical for system operation. The vulnerability is classified under CWE-476 as a NULL Pointer Dereference, which is a well-documented weakness in software security that directly impacts system reliability.
Mitigation strategies for this vulnerability involve applying the official kernel patch that modifies the clk_wzrd_register_divider() function to properly handle error conditions returned by devm_clk_hw_register(). The fix implements immediate error return when registration fails, preventing the subsequent dereference of the error pointer. System administrators should prioritize updating kernel versions to include this patch, particularly in production environments where stability is paramount. The solution aligns with ATT&CK technique T1499.004 for Uninstalling/Disabling Security Tools, as it addresses a foundational system component that could be exploited to compromise system integrity. Organizations should also implement automated patch management systems to ensure timely deployment of security fixes, as this vulnerability could potentially be leveraged in supply chain attacks targeting embedded systems. Regular kernel security audits and static analysis tool integration should be maintained to identify similar error handling patterns that could lead to system instability.