CVE-2023-53994: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-53994 is a vulnerability in the Linux kernel's ionic network driver where an unnecessary WARN_ON macro was left in the IRQ allocation/free path, which can trigger a kernel panic when the panic_on_warn kernel parameter is enabled. The fix removes this leftover early-development debug check. Affected versions span Linux kernel commits from 77ceb68e29ccd25d923b6af59e74ecaf736cc4b7 through multiple stable branches. The CVE was published on December 24, 2025, and NVD has not yet assigned a CVSS score (listed as N/A) (Feedly).

The root cause is an unnecessary WARN_ON macro retained in the ionic driver's IRQ allocation and free code paths long after those paths were cleaned up. When the Linux kernel is configured with panic_on_warn=1, any triggered WARN_ON causes an immediate kernel panic, elevating what would otherwise be a benign warning into a denial-of-service condition. No CWE classification has been formally assigned by NVD. The fix, applied across multiple stable kernel branches, simply removes the stale WARN_ON check (Feedly, kernel.org patches).

The primary impact is an availability risk: on systems with panic_on_warn enabled, triggering the WARN_ON in the ionic driver's IRQ path could cause a kernel panic and system crash, resulting in a denial of service. There is no known confidentiality or integrity impact, and the vulnerability does not enable code execution or privilege escalation. The scope is limited to systems using Cisco/AMD ionic network adapters with the affected kernel versions and the panic_on_warn parameter set (Feedly).

The fix has been backported to multiple stable Linux kernel branches. Patched versions include kernel 5.4.251+, 5.10.188+, 5.15.121+, 6.1.40+, 6.4.5+, and 6.5+. Administrators should update to a patched kernel version for their distribution. As a short-term workaround, disabling panic_on_warn (i.e., ensuring kernel.panic_on_warn=0) will prevent the WARN_ON from causing a kernel panic, though upgrading remains the recommended remediation (Feedly, kernel.org patches).