CVE-2024-46811 in Linux
Summary
by MITRE • 09/27/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/amd/display: Fix index may exceed array range within fpu_update_bw_bounding_box
[Why]
Coverity reports OVERRUN warning. soc.num_states could be 40. But array range of bw_params->clk_table.entries is 8.
[How]
Assert if soc.num_states greater than 8.
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Analysis
by VulDB Data Team • 11/19/2025
The vulnerability identified as CVE-2024-46811 resides within the Linux kernel's display subsystem, specifically in the AMD display driver component under the direct rendering manager framework. This issue manifests as a potential buffer overflow condition that could compromise system stability and security. The flaw occurs in the fpu_update_bw_bounding_box function where the driver attempts to process display bandwidth parameters for AMD graphics hardware. The vulnerability stems from inadequate bounds checking when handling the number of states reported by the system on chip configuration.
The technical root cause of this vulnerability can be traced to a mismatch between the expected array dimensions and the actual data being processed. According to Coverity static analysis reports, the soc.num_states parameter can assume a value of up to 40, while the target array bw_params->clk_table.entries has a fixed dimension of only 8 elements. This fundamental mismatch creates an exploitable condition where array indexing operations may access memory locations beyond the allocated buffer boundaries. The vulnerability falls under the CWE-129 category of Improper Validation of Array Index, which is a well-documented weakness in software systems where array indices are not properly validated before use.
The operational impact of this vulnerability extends beyond simple system instability, potentially enabling attackers to execute arbitrary code or cause denial of service conditions within the graphics processing subsystem. When the display driver processes bandwidth parameters for AMD graphics hardware, the out-of-bounds memory access could result in kernel memory corruption, leading to system crashes or potentially more severe security implications. The issue affects systems running Linux kernels with AMD graphics drivers, particularly those utilizing the display power management features that rely on the affected function. The vulnerability represents a critical concern for embedded systems and servers that depend on stable graphics processing capabilities.
The mitigation strategy for CVE-2024-46811 involves implementing a defensive programming approach that validates the soc.num_states parameter against the array bounds before any indexing operations occur. The fix requires adding an assertion check that prevents execution when soc.num_states exceeds the maximum supported array size of 8 elements. This approach aligns with the ATT&CK framework's defensive techniques for preventing exploitation through input validation and bounds checking. System administrators should prioritize applying the kernel patches that implement this assertion check, as the vulnerability exists in the core graphics driver functionality that handles display bandwidth management. The fix essentially prevents the driver from operating with configurations that exceed the supported hardware capabilities, thereby eliminating the potential for memory corruption while maintaining system stability.
This vulnerability demonstrates the critical importance of proper input validation in kernel space drivers, where buffer overflows can lead to severe security implications. The fix represents a typical defensive programming solution that prevents the exploitation of array indexing errors by ensuring data integrity before processing. The issue highlights the necessity of comprehensive testing and static analysis tools like Coverity in identifying potential security flaws before they can be exploited in real-world scenarios. Organizations should ensure their Linux kernel versions include the patched driver components to protect against potential exploitation of this vulnerability in their graphics processing environments.