CVE-2023-53479: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53479 is a use-after-free (UAF) vulnerability in the Linux kernel's CXL (Compute Express Link) ACPI driver, specifically within the cxl_parse_cfmws() function. The flaw was detected by KASAN and KFENCE memory safety tools and disclosed on October 1, 2025. It affects Linux kernel versions 6.0 through 6.1.42, 6.2 through 6.4.7, and 6.5-rc1 through 6.5-rc3. The vulnerability carries a CVSS v3.1 base score of 7.8 (High) (Feedly, NVD).

The root cause is a use-after-free condition (CWE-416) in drivers/cxl/acpi.c. During the cxl_decoder_add() failure path in cxl_parse_cfmws(), put_device() is called to release the cxld device object; however, a subsequent dev_err() call then dereferences the now-freed cxld pointer, triggering the UAF. The fix replaces the dangling pointer reference with local variables and updates the resource print format to use the %pr format specifier, eliminating the access to freed memory. Exploitation requires local access and low privileges, and can be triggered during CXL device initialization or error conditions on systems with CXL-capable hardware (Feedly, NVD).

Successful exploitation of this vulnerability by a local, low-privileged attacker could result in kernel memory corruption, potentially leading to information disclosure, system crash (denial of service), or privilege escalation. The impact is limited to systems equipped with CXL-capable hardware running affected kernel versions, and the vulnerability does not expose a remote attack surface. All three CIA pillars are rated High in the CVSS assessment, reflecting the potential for full kernel compromise (Feedly).

The vulnerability has been patched in Linux kernel versions 6.1.43, 6.4.8, and 6.5 (mainline). Administrators should update to one of these fixed versions as soon as possible, prioritizing systems running CXL-capable hardware. Patches are available at the upstream kernel stable repository (kernel.org patch 1, kernel.org patch 2, kernel.org patch 3). No configuration-based workaround is available; patching is the only remediation (Feedly).