CVE-2022-48927 in Linux
Summary
by MITRE • 08/22/2024
In the Linux kernel, the following vulnerability has been resolved:
iio: adc: tsc2046: fix memory corruption by preventing array overflow
On one side we have indio_dev->num_channels includes all physical channels + timestamp channel. On other side we have an array allocated only for physical channels. So, fix memory corruption by ARRAY_SIZE() instead of num_channels variable.
Note the first case is a cleanup rather than a fix as the software timestamp channel bit in active_scanmask is never set by the IIO core.
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Analysis
by VulDB Data Team • 08/10/2025
The vulnerability CVE-2022-48927 represents a memory corruption issue within the Linux kernel's Industrial I/O (IIO) subsystem, specifically affecting the TSC2046 touchscreen controller driver. This flaw stems from a fundamental mismatch in how channel counts are handled during driver initialization and memory allocation processes. The issue manifests when the driver attempts to manage both physical channels and a software-generated timestamp channel, creating a scenario where memory boundaries are improperly calculated and potentially violated.
The technical root cause of this vulnerability lies in the improper handling of channel enumeration and memory allocation within the IIO subsystem architecture. The indio_dev->num_channels parameter encompasses all available channels including both physical sensor channels and a software timestamp channel that is automatically managed by the IIO core. However, the underlying array allocation mechanism only provisions memory space for the physical channels themselves, creating a discrepancy that can result in buffer overflows when the driver attempts to access memory locations beyond the allocated array boundaries. This type of memory corruption vulnerability aligns with CWE-121, which addresses stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios.
The operational impact of this vulnerability extends beyond simple memory corruption, potentially allowing malicious actors to execute arbitrary code or cause system instability within embedded Linux systems that utilize the TSC2046 touchscreen controller. The vulnerability affects systems where the IIO subsystem is actively managing touchscreen input devices, particularly in industrial automation, embedded systems, and IoT devices that rely on precise sensor data handling. Attackers could exploit this memory corruption to gain unauthorized access to system resources or cause denial of service conditions that would disrupt critical operations in environments where reliable input device functionality is essential.
This vulnerability specifically impacts the TSC2046 touchscreen controller driver within the Linux kernel's IIO framework, where the software timestamp channel bit in the active_scanmask is never actually set by the IIO core, making this a cleanup rather than a functional fix. The resolution addresses the memory corruption by modifying the allocation logic to use ARRAY_SIZE() instead of the num_channels variable, ensuring that memory boundaries properly correspond to the actual array size rather than the total channel count including software-managed elements. The fix aligns with ATT&CK technique T1068 by addressing privilege escalation through kernel memory corruption vulnerabilities, and represents a defensive programming approach that prevents buffer overflows through proper boundary checking.
The mitigation strategy for CVE-2022-48927 involves updating to a patched kernel version that implements the corrected memory allocation logic, ensuring that the ARRAY_SIZE() macro is properly utilized instead of the total channel count variable. System administrators should prioritize patching embedded devices and industrial control systems that utilize the TSC2046 driver, particularly those in critical infrastructure environments where input device reliability is paramount. Organizations should also implement monitoring for unusual system behavior that might indicate memory corruption or buffer overflow exploitation attempts, as the vulnerability's impact could manifest through system crashes or unexpected device malfunctions. The fix demonstrates proper software engineering practices by ensuring that memory allocation matches the actual data structures being used, preventing the type of buffer overflow conditions that could be exploited for privilege escalation or system compromise in embedded Linux environments.