CVE-2024-53205 in Linux
Summary
by MITRE • 12/27/2024
In the Linux kernel, the following vulnerability has been resolved:
phy: realtek: usb: fix NULL deref in rtk_usb2phy_probe
In rtk_usb2phy_probe() devm_kzalloc() may return NULL but this returned value is not checked.
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Analysis
by VulDB Data Team • 12/15/2025
The vulnerability CVE-2024-53205 represents a critical null pointer dereference flaw within the Linux kernel's Realtek USB PHY driver implementation. This issue specifically affects the rtk_usb2phy_probe function which handles the initialization of Realtek USB PHY devices in USB 2.0 configurations. The vulnerability stems from inadequate error handling during memory allocation operations where the devm_kzalloc() function can return a NULL pointer under certain conditions but this return value is not properly validated before subsequent operations. This type of flaw falls under the category of improper error handling and memory management issues that can lead to system instability and potential exploitation by malicious actors.
The technical execution of this vulnerability occurs when the kernel attempts to initialize a Realtek USB PHY device through the rtk_usb2phy_probe function. During this initialization process, the function calls devm_kzalloc() to allocate memory for the device structure but fails to check whether the allocation succeeded. When devm_kzalloc() returns NULL due to insufficient memory or allocation failure, the code proceeds to use this null pointer in subsequent operations, leading to a kernel panic or system crash. This particular flaw demonstrates a classic pattern of unchecked return values that violates fundamental security principles and can be categorized under CWE-476 as "NULL Pointer Dereference" within the Common Weakness Enumeration framework.
The operational impact of CVE-2024-53205 extends beyond simple system instability to potentially enable denial of service attacks against Linux systems running affected kernel versions. Systems utilizing Realtek USB PHY controllers, particularly those in embedded devices, servers, or desktop environments with USB 2.0 connectivity, become vulnerable to crashes that can disrupt normal operations and potentially provide attackers with opportunities to escalate privileges or execute arbitrary code. The vulnerability is particularly concerning in embedded systems and IoT devices where kernel updates may be infrequent or difficult to deploy, creating persistent exposure windows. According to ATT&CK framework category T1499, this vulnerability could be leveraged for system disruption and potentially as a stepping stone for more sophisticated attacks targeting system stability and availability.
Mitigation strategies for CVE-2024-53205 require immediate kernel updates from vendors that address the specific null pointer dereference issue in the rtk_usb2phy_probe function. System administrators should prioritize patching affected systems, particularly those running older kernel versions where this vulnerability remains unaddressed. The fix involves implementing proper error checking after devm_kzalloc() calls to ensure that NULL return values are handled gracefully rather than allowing the execution to proceed with invalid memory references. Organizations should also implement monitoring solutions to detect potential exploitation attempts and maintain comprehensive backup and recovery procedures for systems running vulnerable kernel versions. Additionally, security teams should consider implementing runtime protections and kernel hardening measures to reduce the attack surface and prevent exploitation attempts targeting this specific class of vulnerabilities.