CVE-2023-52826 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/panel/panel-tpo-tpg110: fix a possible null pointer dereference
In tpg110_get_modes(), the return value of drm_mode_duplicate() is assigned to mode, which will lead to a NULL pointer dereference on failure of drm_mode_duplicate(). Add a check to avoid npd.
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Analysis
by VulDB Data Team • 06/20/2025
The vulnerability CVE-2023-52826 represents a critical null pointer dereference issue within the Linux kernel's display subsystem, specifically affecting the drm/panel/panel-tpo-tpg110 driver component. This flaw exists in the tpg110_get_modes() function where the driver fails to properly validate the return value from drm_mode_duplicate() before proceeding with subsequent operations. The vulnerability stems from inadequate error handling mechanisms that do not account for potential failures during mode duplication operations, creating a scenario where a null pointer dereference can occur when the drm_mode_duplicate() function returns NULL upon encountering an error condition.
The technical implementation of this vulnerability demonstrates a classic improper error handling pattern that violates fundamental security principles. When drm_mode_duplicate() fails to duplicate a display mode, it returns NULL to indicate the failure condition, but the tpg110_get_modes() function does not check this return value before attempting to use the resulting pointer. This pattern aligns with CWE-476 which specifically addresses null pointer dereference vulnerabilities, where a null pointer is dereferenced without proper validation. The flaw occurs in the context of display mode management within the Direct Rendering Manager subsystem, which is responsible for handling graphics hardware interfaces and display configuration in Linux systems.
The operational impact of this vulnerability extends beyond simple system instability to potentially enable denial of service conditions and, in theoretical scenarios, could provide an entry point for privilege escalation attacks. When the null pointer dereference occurs, it typically results in a kernel oops or system crash, effectively causing a denial of service for display functionality. The vulnerability affects systems running Linux kernel versions that include the problematic drm/panel/panel-tpo-tpg110 driver, particularly those utilizing TPO TPG110 display panels or compatible hardware. From an attacker perspective, this vulnerability could be leveraged in a denial of service attack against systems that rely on proper display management functionality, potentially disrupting critical user interfaces or embedded systems with display capabilities.
Mitigation strategies for CVE-2023-52826 primarily focus on applying the official kernel patch that introduces proper null pointer validation before dereferencing the mode pointer. The recommended approach involves checking the return value of drm_mode_duplicate() and handling the NULL case appropriately, typically by returning an error code or skipping the problematic mode configuration. System administrators should prioritize applying kernel updates from their distribution vendors or directly from the Linux kernel stable release process. Additionally, organizations implementing the affected driver should consider implementing runtime monitoring for kernel oops conditions and system crashes related to display subsystem operations. This vulnerability also highlights the importance of proper defensive programming practices in kernel space code, aligning with ATT&CK technique T1499.004 which addresses the exploitation of system resource exhaustion, as denial of service conditions can effectively consume system resources and disrupt normal operations. The fix demonstrates a fundamental principle of secure coding where all function return values must be validated before use, particularly in kernel space where such failures can have catastrophic consequences for system stability and security.