CVE-2024-42119 in Linux
Summary
by MITRE • 07/30/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Skip finding free audio for unknown engine_id
[WHY]
ENGINE_ID_UNKNOWN = -1 and can not be used as an array index. Plus, it also means it is uninitialized and does not need free audio.
[HOW]
Skip and return NULL.
This fixes 2 OVERRUN issues reported by Coverity.
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Analysis
by VulDB Data Team • 09/29/2025
The vulnerability identified as CVE-2024-42119 resides within the Linux kernel's display subsystem, specifically in the AMD display driver component known as drm/amd/display. This issue manifests as a potential out-of-bounds memory access condition that could lead to system instability or arbitrary code execution. The flaw occurs in the audio handling mechanism where the driver attempts to process audio resources for display engines without proper validation of engine identifiers. The root cause stems from the driver's failure to properly handle the ENGINE_ID_UNKNOWN constant value, which is defined as -1, when processing audio allocation and deallocation operations.
The technical implementation of this vulnerability involves a critical flaw in array indexing logic where the driver uses ENGINE_ID_UNKNOWN as an array index without proper bounds checking or validation. This constant value represents an uninitialized state and should never be treated as a valid engine identifier for audio resource management. When the driver encounters this invalid identifier, it attempts to access memory locations outside the legitimate array bounds, creating opportunities for memory corruption and potential exploitation. The vulnerability was identified through static analysis tools and specifically reported by Coverity as two separate out-of-bounds read/write conditions that could be triggered during normal operation of the display subsystem.
The operational impact of this vulnerability extends beyond simple memory corruption to potentially enable privilege escalation and system compromise. An attacker who can trigger the specific code path leading to this out-of-bounds access could potentially execute arbitrary code with kernel-level privileges, effectively gaining complete control over the affected system. This risk is particularly concerning in environments where untrusted users have access to display operations or where the system handles multimedia content from external sources. The vulnerability affects systems running Linux kernels with AMD display drivers, particularly those supporting newer hardware configurations that utilize the affected display engine management logic. The flaw demonstrates a classic software security issue where improper input validation leads to memory safety violations that can be exploited to bypass security mechanisms.
The fix implemented for CVE-2024-42119 involves modifying the driver's audio resource management code to explicitly check for the ENGINE_ID_UNKNOWN value before attempting any array operations. When this invalid identifier is detected, the driver now simply skips the audio resource processing and returns NULL, preventing the out-of-bounds memory access. This approach follows secure coding practices by ensuring that all array indices are validated against legitimate bounds before access. The solution aligns with CWE-129, which addresses improper validation of array indices, and addresses the specific ATT&CK technique T1068, which involves exploiting privileges to execute malicious code. The patch represents a defensive programming approach that prevents uninitialized memory access patterns while maintaining the expected functionality of the display driver. This fix has been integrated into the mainline Linux kernel and represents a critical security update for all affected systems running AMD display hardware. The resolution demonstrates the importance of proper input validation in kernel space code and highlights how seemingly minor logic flaws can create significant security vulnerabilities in operating system components.