CVE-2023-54248: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-54248 is a NULL pointer dereference vulnerability in the Linux kernel's NTFS3 filesystem driver (fs/ntfs3). The flaw arises because the return value of kmemdup() — which can return NULL on memory allocation failure — was not checked, potentially leading to a NULL pointer dereference. The vulnerability affects Linux kernel versions starting from the introduction of the NTFS3 driver (around 5.15) up to the patched stable releases. Fixes were backported to stable branches including 5.15.111, 6.1.28, 6.2.15, 6.3.2, and 6.4. The CVE was published on December 30, 2025, with a CVSS base score of 0.0 (no severity rating assigned at time of publication) (Feedly, ENISA EUVD).

The root cause is a missing NULL pointer check after a call to kmemdup() in the NTFS3 filesystem driver (fs/ntfs3), classified as CWE-476 (NULL Pointer Dereference). kmemdup() is a kernel memory duplication function that can return NULL when memory allocation fails; without validating the return value, subsequent code may dereference the NULL pointer, causing a kernel panic or system crash. Exploitation would require the ability to trigger the specific NTFS3 code path — typically by mounting or interacting with a crafted NTFS filesystem image. Patches were applied across multiple stable kernel branches via commits such as 952bbfce, 7898db22, 9f36704a, cdcdfd57, and e6c3cef2 (Feedly, ENISA EUVD).

Successful exploitation of this vulnerability can cause a kernel NULL pointer dereference, resulting in a system crash (kernel panic) and denial of service. Because the flaw resides in kernel space, it affects the availability of the entire system rather than a single user-space process. There is no evidence of confidentiality or integrity impact beyond the crash, and lateral movement or data exfiltration are not expected outcomes of this specific vulnerability (Feedly).

Apply the relevant stable kernel update that includes the fix for CVE-2023-54248. Patched versions include Linux kernel 5.15.111, 6.1.28, 6.2.15, 6.3.2, and 6.4. As a workaround on systems that do not require NTFS3 support, administrators can blacklist or disable the ntfs3 kernel module (echo 'blacklist ntfs3' >> /etc/modprobe.d/blacklist.conf) to prevent the vulnerable code path from being triggered. Upgrading to a patched kernel version is the recommended long-term remediation (Feedly, ENISA EUVD).