CVE-2025-38612 in Linux
Summary
by MITRE • 08/19/2025
In the Linux kernel, the following vulnerability has been resolved:
staging: fbtft: fix potential memory leak in fbtft_framebuffer_alloc()
In the error paths after fb_info structure is successfully allocated, the memory allocated in fb_deferred_io_init() for info->pagerefs is not freed. Fix that by adding the cleanup function on the error path.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 01/21/2026
The vulnerability CVE-2025-38612 represents a memory leak issue within the Linux kernel's framebuffer subsystem, specifically affecting the fbtft driver used for various display devices. This flaw exists in the staging directory of the kernel, indicating it is part of a driver that may not have undergone the full stabilization process typical of core kernel components. The vulnerability manifests in the fbtft_framebuffer_alloc() function where proper memory management fails during error handling scenarios. The issue occurs when the fb_info structure is successfully allocated but subsequent operations fail, leaving allocated memory from fb_deferred_io_init() unreleased.
The technical implementation of this vulnerability stems from inadequate error path handling within the framebuffer allocation process. When fb_info structure allocation succeeds but later operations encounter failures, the memory allocated for info->pagerefs through fb_deferred_io_init() is not properly freed. This represents a classic memory leak pattern where resources are acquired but not released during exceptional conditions. The flaw specifically affects the fbtft driver which is designed to support various framebuffer devices including LCD displays and other embedded graphics hardware. The memory leak occurs in the staging subsystem, suggesting this may be a driver that is still under development or testing phases.
From an operational perspective, this vulnerability creates a persistent memory consumption issue that can accumulate over time, potentially leading to system performance degradation or memory exhaustion. While the individual memory leak may appear minor, repeated occurrences in active systems can result in significant resource waste, particularly on embedded devices with limited memory resources. The impact is more pronounced in systems that frequently allocate and deallocate framebuffer resources or those running long-term without rebooting. The vulnerability affects the stability and reliability of display subsystems, potentially causing display corruption or system instability when memory resources become constrained.
The fix for CVE-2025-38612 addresses the root cause by implementing proper cleanup functions on error paths. This follows standard memory management practices and aligns with common security guidelines for preventing resource leaks. The solution involves adding appropriate cleanup code that ensures memory allocated in fb_deferred_io_init() is properly freed when error conditions occur during the framebuffer allocation process. This remediation approach is consistent with the principle of defensive programming and proper resource management. The fix demonstrates adherence to secure coding practices that prevent memory leaks by ensuring all allocated resources are properly released regardless of execution path taken.
This vulnerability can be categorized under CWE-401 as a failure to release memory, representing a fundamental resource management issue. From an ATT&CK perspective, this vulnerability falls under the category of privilege escalation and resource exhaustion, potentially enabling an attacker to consume system resources over time. The vulnerability may be exploited by malicious actors who can trigger repeated allocation failures in the framebuffer subsystem, leading to progressive memory consumption. The impact is particularly concerning in embedded systems and IoT devices where memory is limited and system stability is critical. The fix addresses the vulnerability by ensuring proper error handling and resource cleanup, which aligns with the principle of least privilege and resource isolation in secure system design.
The resolution of this vulnerability demonstrates the importance of thorough error path testing and memory management in kernel development. Proper cleanup functions should be implemented for all resource allocations, especially in staging drivers where the code may not have undergone the same level of rigorous testing as core kernel components. This vulnerability highlights the need for comprehensive testing of error conditions and the importance of maintaining proper resource accounting even in driver subsystems that may not be fully matured. The fix serves as a reminder to kernel developers about the critical nature of resource management during error handling scenarios and the potential impact of memory leaks on system stability and security.