CVE-2026-43354 in Linux
Summary
by MITRE • 05/08/2026
In the Linux kernel, the following vulnerability has been resolved:
iio: proximity: hx9023s: Protect against division by zero in set_samp_freq
Avoid division by zero when sampling frequency is unspecified.
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Analysis
by VulDB Data Team • 09/13/2026
The vulnerability identified in the Linux kernel affects the industrial input/output subsystem specifically within the proximity sensor driver for the hx9023s device. This issue manifests as a potential division by zero error that occurs when the sampling frequency parameter is not properly specified during device initialization or configuration. The problem resides in the set_samp_freq function which handles the configuration of sampling frequencies for proximity sensors. When the sampling frequency value is undefined or set to zero, the driver attempts to perform a mathematical division operation that results in a kernel panic or system crash. This type of vulnerability represents a classic denial of service condition that can be exploited to disrupt system operations. The issue falls under the category of improper input validation and error handling within kernel space drivers. According to CWE classification, this vulnerability maps to CWE-369: Divide by Zero, which is a well-documented weakness in software systems where division operations are performed without proper validation of the divisor. The vulnerability demonstrates a failure in defensive programming practices where the driver code does not adequately check for invalid input values before performing arithmetic operations. When analyzed through the ATT&CK framework, this vulnerability could be categorized under privilege escalation techniques or denial of service attacks, as it affects kernel-level functionality and can cause system instability. The impact extends beyond simple service disruption since kernel-level division by zero errors can lead to complete system crashes or require system reboots to recover. The vulnerability is particularly concerning in embedded systems or industrial environments where continuous operation is critical and unexpected system failures can lead to significant operational disruptions. The fix implemented addresses the root cause by adding proper validation checks to ensure that the sampling frequency parameter is valid before any division operations are attempted. This defensive programming approach prevents the kernel from executing invalid mathematical operations that could compromise system stability and security. The solution demonstrates the importance of input sanitization and parameter validation in kernel space programming where errors can have catastrophic consequences.
The technical flaw in this vulnerability stems from the absence of proper parameter validation within the kernel driver's sampling frequency configuration routine. When the set_samp_freq function receives an invalid or zero sampling frequency value, it proceeds directly to perform division operations without verifying that the divisor is non-zero. This pattern of behavior is particularly dangerous in kernel space where such errors can lead to immediate system termination rather than graceful error handling. The vulnerability represents a failure in the driver's error handling architecture and indicates a lack of defensive programming practices that are essential for maintaining kernel stability. The specific nature of this issue makes it particularly susceptible to exploitation through malformed device configuration requests or improper device initialization sequences. From a security perspective, this vulnerability could potentially be leveraged by malicious actors to create denial of service conditions or to probe for other kernel-level weaknesses. The vulnerability's impact is amplified in environments where multiple proximity sensors are managed by a single driver instance, as a single malformed configuration could affect the entire sensor subsystem. The fix addresses this by implementing a pre-division validation check that ensures any sampling frequency value meets minimum requirements before arithmetic operations are performed.
Operational impact of this vulnerability extends beyond immediate system crashes to encompass broader reliability concerns in production environments. The potential for unexpected system panics during normal operation can severely impact industrial automation systems, automotive applications, or any environment where continuous monitoring is required. In critical infrastructure scenarios, such as manufacturing plants or telecommunications networks, the disruption caused by this vulnerability could result in production delays or service interruptions with significant financial implications. The vulnerability affects the IIO subsystem's ability to properly manage proximity sensor data acquisition, potentially leading to data loss or incomplete sensor readings that could compromise system monitoring capabilities. Organizations relying on Linux-based systems for industrial control or embedded applications face particular risk since these environments often operate with minimal user intervention and may not have immediate recovery mechanisms in place. The vulnerability also impacts system maintainability as it may require manual intervention to restore normal operation after a crash occurs, potentially requiring system downtime for recovery procedures. Furthermore, the instability introduced by this vulnerability can mask other underlying issues or create cascading failures within complex systems where multiple sensors and subsystems interact. The operational risk is compounded by the fact that such kernel-level issues are often difficult to diagnose and may require specialized debugging tools or kernel analysis techniques to identify the root cause.
Mitigation strategies for this vulnerability should begin with immediate deployment of the patched kernel version that includes the division by zero protection mechanism. System administrators should prioritize updating all affected systems, particularly those in critical operational environments where reliability is paramount. The fix implemented in the kernel update addresses the specific vulnerability by introducing proper parameter validation before division operations are executed, thereby preventing the kernel from entering an undefined state. Organizations should implement comprehensive testing procedures to verify that the patch does not introduce compatibility issues with existing sensor configurations or device drivers. Additional defensive measures include implementing robust monitoring systems that can detect and alert on system instability or kernel panic events that may indicate the presence of similar vulnerabilities. Network segmentation and access control measures should be maintained to limit potential exploitation vectors, particularly in environments where untrusted users or processes may have access to sensor configuration interfaces. Regular security assessments of kernel components and device drivers should be conducted to identify and address similar vulnerabilities before they can be exploited. The vulnerability highlights the importance of maintaining up-to-date kernel versions and implementing proper vulnerability management processes that include regular security patching. System hardening practices should also be reinforced, including disabling unnecessary kernel modules and ensuring that only required device drivers are loaded to minimize the attack surface. Long-term security strategies should include regular code reviews of kernel subsystems and driver implementations to identify potential arithmetic operation vulnerabilities and other similar issues that could compromise system stability.