CVE-2023-53858: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53858 is a memory leak vulnerability in the Linux kernel's Samsung TTY serial driver (samsung_tty). Specifically, the function s3c24xx_serial_getclk() fails to free a clock object (clk) when clk_get_rate() returns an error, resulting in a kernel memory leak. The vulnerability affects Linux kernel versions starting from commit 5f5a7a5578c5 and was published on December 9, 2025. Fixed versions include Linux 5.4.251, 5.10.188, 5.15.121, 4.14.322, 4.19.291, 6.1.40, 6.4.5, and 6.5. The CVSS estimate is Medium, with an EPSS score of approximately 0.024% (Feedly, EUVD).

The root cause is a missing resource cleanup on an error path in the s3c24xx_serial_getclk() function within the drivers/tty/serial/samsung_tty.c file of the Linux kernel (CWE-401: Missing Release of Memory after Effective Lifetime). When clk_get_rate() fails, the function returns without calling the appropriate clock release function on the previously allocated clk object, causing a kernel memory leak. Exploitation would require local access to a system running an affected kernel version on hardware using the Samsung S3C24xx/Exynos serial driver. Patches are available as commits to multiple stable kernel branches (Feedly, EUVD).

The primary impact of this vulnerability is a kernel memory leak, which can gradually degrade system availability by exhausting kernel memory resources over time, particularly on embedded or mobile systems using Samsung S3C24xx/Exynos serial hardware. There is no direct confidentiality or integrity impact, and the vulnerability does not enable privilege escalation or remote code execution. The practical risk is limited to availability degradation on affected hardware platforms (Feedly).

Apply the upstream Linux kernel patches that address this memory leak. Fixed versions are available across multiple stable branches: 5.4.251, 5.10.188, 5.15.121, 4.14.322, 4.19.291, 6.1.40, 6.4.5, and 6.5. Administrators should update to a patched kernel version appropriate for their distribution. SUSE has also issued advisories (SUSE-2026-0281-1 and SUSE-2026-20876-1) incorporating these fixes (Feedly, Linux Security SUSE).