CVE-2023-53687 in Linux
Summary
by MITRE • 10/07/2025
In the Linux kernel, the following vulnerability has been resolved:
tty: serial: samsung_tty: Fix a memory leak in s3c24xx_serial_getclk() when iterating clk
When the best clk is searched, we iterate over all possible clk.
If we find a better match, the previous one, if any, needs to be freed. If a better match has already been found, we still need to free the new one, otherwise it leaks.
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Analysis
by VulDB Data Team • 03/01/2026
The vulnerability identified as CVE-2023-53687 represents a memory leak within the Linux kernel's serial tty subsystem, specifically affecting the samsung_tty driver implementation. This issue manifests in the s3c24xx_serial_getclk() function where the kernel attempts to identify and configure the optimal clock source for serial communication on Samsung-based embedded systems. The flaw occurs during the iterative process of searching through available clock configurations, where the kernel fails to properly manage memory allocation and deallocation patterns. The vulnerability demonstrates a classic memory management error that can lead to progressive resource exhaustion over time.
The technical implementation of this vulnerability stems from improper handling of clock resource management within the Samsung serial driver framework. When the kernel iterates through multiple clock configurations to find the optimal match, it correctly identifies when a better clock source is discovered and frees the previous allocation. However, the code fails to properly clean up newly allocated clock resources when a better match has already been identified earlier in the iteration process. This creates a scenario where multiple clock structures remain allocated in memory without proper cleanup, resulting in a memory leak that accumulates over time. The issue is particularly concerning in embedded systems where memory resources are constrained and continuous operation is expected.
The operational impact of this memory leak extends beyond simple resource consumption, potentially leading to system instability and reduced performance in embedded Linux environments. As the leak accumulates over time, it can cause gradual memory pressure that may eventually lead to system slowdowns, application failures, or even complete system crashes. This vulnerability affects devices running Samsung-based embedded systems that utilize the s3c24xx serial driver, including various IoT devices, industrial controllers, and embedded communication modules. The memory leak compounds over extended periods of operation, making it particularly dangerous in environments where systems operate continuously without rebooting.
Mitigation strategies for CVE-2023-53687 involve applying the kernel patch that corrects the clock resource management logic within the samsung_tty driver. The fix ensures that all allocated clock structures are properly freed regardless of the iteration path taken during clock selection. System administrators should prioritize updating their embedded Linux systems to versions containing the patched kernel code, particularly in production environments where continuous operation is critical. Additionally, monitoring memory usage patterns on affected systems can help detect the accumulation of leaked memory before it reaches critical levels. Organizations should also implement regular system maintenance procedures that include scheduled reboots to clear accumulated memory leaks, though this represents a temporary workaround rather than a permanent solution. This vulnerability aligns with CWE-401, which specifically addresses improper release of memory, and represents a classic example of resource management flaws that can be exploited to cause denial of service conditions in embedded systems.