CVE-2023-53197: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53197 is a memory leak vulnerability in the Linux kernel's USB UHCI (Universal Host Controller Interface) debugfs implementation. The flaw occurs when debugfs_lookup() is called without subsequently invoking dput() on the returned dentry, causing gradual memory consumption over time. Affected kernel versions include 5.x through before 5.15.100, 5.16 through before 6.1.18, and 6.2 through before 6.2.5. It was published on September 15, 2025, and carries a CVSS v3.1 base score of 5.5 (Medium) (Red Hat Advisory, Red Hat Bugzilla).

The root cause is classified as CWE-401 (Missing Release of Memory after Effective Lifetime). In the UHCI USB host controller driver, a call to debugfs_lookup() returns a dentry reference that must be released via dput() when no longer needed; omitting this call causes the kernel to accumulate unreleased memory references over time. The fix replaces the debugfs_lookup() call with debugfs_lookup_and_remove(), which atomically performs the lookup and cleanup in a single operation. Exploitation requires local, low-privileged access and no user interaction, making it a low-complexity local attack vector (Red Hat Advisory, Red Hat Bugzilla).

Successful exploitation by a local low-privileged attacker can cause gradual memory exhaustion on the affected system. Over time, this progressive memory consumption can degrade system performance, cause instability, and potentially result in a denial of service condition as kernel memory resources are depleted. There is no impact on confidentiality or integrity; the vulnerability is limited to availability (Red Hat Advisory).

There is no public proof-of-concept exploit available, and no evidence of in-the-wild exploitation has been observed. The vulnerability is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog. The EPSS score is approximately 0.018%, reflecting a very low probability of exploitation in the near term (Red Hat Advisory, Red Hat Bugzilla).

Patches are available for multiple stable kernel branches: upgrade to Linux kernel 5.15.100 or later, 6.1.18 or later, or 6.2.5 or later to resolve the issue. The upstream fixes are available in the kernel stable tree commits 0a3f82c, 9cb88847, c6af1dbc, and e529aeb7. For systems that cannot be immediately patched, administrators should monitor memory usage and consider restarting affected services or systems exhibiting unusual memory consumption, and limit local user access to critical system resources (Red Hat Bugzilla).