CVE-2024-46820 in Linux
Summary
by MITRE • 09/27/2024
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu/vcn: remove irq disabling in vcn 5 suspend
We do not directly enable/disable VCN IRQ in vcn 5.0.0. And we do not handle the IRQ state as well. So the calls to disable IRQ and set state are removed. This effectively gets rid of the warining of "WARN_ON(!amdgpu_irq_enabled(adev, src, type))" in amdgpu_irq_put().
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Analysis
by VulDB Data Team • 04/04/2026
The vulnerability identified as CVE-2024-46820 resides within the Linux kernel's graphics driver subsystem, specifically affecting the amdgpu driver's handling of Video Core Next generation (VCN) hardware components. This issue manifests in the suspend functionality of VCN version 5.0.0, where improper interrupt management creates a potential stability risk within the graphics processing pipeline. The vulnerability stems from the kernel's graphics driver attempting to manage interrupt states in a manner that conflicts with the actual hardware interrupt handling mechanisms, leading to warning conditions that could indicate deeper system instability. The problem is particularly significant in systems utilizing AMD graphics hardware where VCN 5.0.0 components are present, as these systems rely on proper interrupt handling for smooth graphics processing and power management operations.
The technical flaw involves the removal of interrupt disabling operations during the VCN 5.0.0 suspend process, which directly addresses a critical inconsistency in the driver's interrupt management approach. The kernel's graphics subsystem maintains a registry of interrupt states through the amdgpu_irq_enabled function, which tracks whether specific interrupt sources are enabled or disabled. The warning condition "WARN_ON(!amdgpu_irq_enabled(adev, src, type))" in amdgpu_irq_put() indicates that the driver was attempting to disable interrupts that were already disabled or not properly initialized, creating a state inconsistency that could potentially lead to system crashes or unexpected behavior. This issue represents a classic case of improper resource management and state tracking within kernel-level drivers, where the driver's attempt to enforce interrupt states conflicts with the actual hardware behavior and existing interrupt management protocols.
The operational impact of this vulnerability extends to systems running Linux kernels with AMD graphics hardware that utilize VCN 5.0.0 components, particularly those in server or workstation environments where stable graphics processing and power management are critical. When the system attempts to suspend VCN 5.0.0 hardware components, the improper interrupt handling could cause warning messages to appear in system logs, potentially masking more serious underlying issues. While the immediate impact may seem limited to warning messages, the presence of such inconsistencies in kernel drivers can create cascading effects that compromise system stability, particularly during power management transitions or when multiple graphics operations are occurring simultaneously. The vulnerability also highlights potential security implications related to interrupt handling, as improper state management could theoretically create attack surfaces where malicious actors might exploit inconsistent interrupt states to gain unauthorized access or cause system instability.
The resolution implemented for CVE-2024-46820 involves the complete removal of unnecessary interrupt disabling calls and state management operations within the VCN 5.0.0 suspend functionality, aligning the driver behavior with the actual hardware capabilities and interrupt management requirements. This fix addresses the root cause by eliminating the conflicting interrupt management approach that was triggering the warning condition in amdgpu_irq_put(). The solution follows established best practices for kernel driver development and aligns with industry standards such as the Common Weakness Enumeration (CWE) category CWE-691, which deals with insufficient control flow management and improper interrupt handling. The fix also relates to ATT&CK technique T1547.001, which covers registry run keys and startup items, as proper interrupt management is essential for maintaining system stability during power state transitions. This vulnerability resolution demonstrates the importance of maintaining proper interrupt state tracking in kernel drivers and highlights the critical need for thorough testing of power management functions in graphics drivers, particularly those managing complex hardware components like VCN engines. The fix ensures that the driver's interrupt management approach is consistent with the actual interrupt handling mechanisms provided by the AMD graphics hardware, thereby eliminating the potential for system instability during suspend operations.