CVE-2023-52753 in Linux
Summary
by MITRE • 05/21/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Avoid NULL dereference of timing generator
[Why & How]
Check whether assigned timing generator is NULL or not before accessing its funcs to prevent NULL dereference.
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Analysis
by VulDB Data Team • 05/21/2024
The vulnerability identified as CVE-2023-52753 represents a critical NULL pointer dereference flaw within the AMD display driver component of the Linux kernel. This issue specifically affects the drm/amd/display subsystem which manages display output for AMD graphics hardware. The vulnerability arises from insufficient input validation during the handling of display timing generators, which are essential components responsible for synchronizing video signals with display hardware. When the system attempts to access display timing generator functions without first verifying their existence, a NULL pointer dereference occurs that can lead to system instability or potential exploitation.
The technical implementation of this vulnerability stems from a missing null check in the display driver code where timing generator objects are accessed without proper validation. According to CWE-476, this represents a NULL pointer dereference weakness that occurs when a pointer expected to reference a valid object is NULL. The flaw exists in the display management code path where timing generators are assigned and subsequently accessed, creating a condition where the driver attempts to call functions on a NULL timing generator object. This type of vulnerability falls under the ATT&CK technique T1059.003 for command and scripting interpreter, as it could potentially be exploited to gain unauthorized access to system resources through display driver manipulation.
The operational impact of this vulnerability extends beyond simple system crashes or hangs, as it could enable attackers to cause denial of service conditions or potentially escalate privileges within the graphics subsystem. When a NULL timing generator is encountered during display configuration operations, the kernel's display driver will attempt to dereference a NULL pointer, resulting in an immediate system crash or panic. This type of vulnerability is particularly concerning in embedded systems or server environments where display functionality may be critical for system management or where automated recovery mechanisms are not present. The vulnerability affects all Linux kernel versions that include the problematic drm/amd/display driver code, making it a widespread concern across various system configurations.
Mitigation strategies for CVE-2023-52753 should focus on implementing proper null pointer validation before accessing timing generator functions. System administrators should prioritize applying the latest kernel updates that contain the patched drm/amd/display driver code, which includes the necessary null checks to prevent the dereference condition. The fix involves adding a conditional check to verify that the timing generator object is not NULL before attempting to access its function pointers, thereby preventing the kernel from crashing when encountering unexpected null values. Organizations should also consider implementing monitoring solutions to detect potential exploitation attempts and ensure that display driver components are regularly updated as part of their overall security maintenance program. This vulnerability demonstrates the importance of input validation in kernel space drivers and highlights the need for comprehensive testing of display subsystems under various configuration scenarios.