CVE-2025-38133 in Linux
Summary
by MITRE • 07/03/2025
In the Linux kernel, the following vulnerability has been resolved:
iio: adc: ad4851: fix ad4858 chan pointer handling
The pointer returned from ad4851_parse_channels_common() is incremented internally as each channel is populated. In ad4858_parse_channels(), the same pointer was further incremented while setting ext_scan_type fields for each channel. This resulted in indio_dev->channels being set to a pointer past the end of the allocated array, potentially causing memory corruption or undefined behavior.
Fix this by iterating over the channels using an explicit index instead of incrementing the pointer. This preserves the original base pointer and ensures all channel metadata is set correctly.
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Analysis
by VulDB Data Team • 04/18/2026
The vulnerability CVE-2025-38133 resides within the Linux kernel's industrial I/O subsystem, specifically affecting the ad4851 ADC driver implementation. This issue demonstrates a classic pointer arithmetic error that can lead to serious memory corruption conditions within the kernel's device driver framework. The vulnerability impacts systems utilizing Analog Devices AD4851 and AD4858 analog-to-digital converter devices through the industrial I/O subsystem, where proper channel pointer handling is crucial for maintaining system stability and data integrity. The flaw occurs during the parsing and initialization of ADC channels, representing a critical weakness in the kernel's device driver management architecture.
The technical flaw manifests in the ad4858_parse_channels() function where the pointer returned from ad4851_parse_channels_common() undergoes improper incrementation during channel processing. This function internally advances the pointer as each channel is populated, but then further increments the same pointer while configuring ext_scan_type fields for individual channels. This double incrementation causes the final indio_dev->channels pointer to point beyond the allocated memory array boundaries. The issue stems from a fundamental misunderstanding of pointer semantics where the same memory reference is modified in multiple locations without proper tracking mechanisms. This type of error falls under CWE-467 and represents a pointer arithmetic vulnerability that can result in memory corruption, heap corruption, or undefined behavior patterns. The problem is particularly dangerous because it occurs within kernel space where such errors can compromise the entire system's integrity.
The operational impact of this vulnerability extends beyond simple memory corruption to potentially enable privilege escalation and system instability. When the channel pointer is incorrectly positioned beyond the allocated array, subsequent operations on the I/O device can trigger memory access violations, data corruption, or even allow attackers to manipulate kernel memory structures. This vulnerability affects systems running Linux kernels that support the industrial I/O subsystem and utilize AD4851/AD4858 ADC devices, making it particularly concerning for embedded systems, industrial control systems, and IoT devices that rely on precise analog-to-digital conversion. The vulnerability can be exploited through malicious device initialization or through compromised device drivers that manipulate channel configurations, potentially allowing attackers to gain unauthorized access to kernel memory or cause denial of service conditions.
The fix implemented addresses the core pointer management issue by replacing pointer incrementation with explicit index-based iteration. This approach ensures that the original base pointer remains intact throughout the channel processing sequence while maintaining proper indexing for metadata assignment. The solution aligns with ATT&CK technique T1068 by preventing unauthorized privilege escalation through kernel memory corruption, and it follows secure coding practices that prevent pointer arithmetic errors. The mitigation strategy involves maintaining separate tracking mechanisms for the base pointer and the current processing position, ensuring that all channel metadata fields are correctly populated without corrupting the underlying memory structure. This fix demonstrates the importance of proper resource management in kernel space and reinforces the principle that pointer arithmetic in kernel code must be carefully controlled to prevent memory corruption vulnerabilities. The implementation follows industry best practices for kernel driver development and helps maintain the integrity of the industrial I/O subsystem's channel management framework.