CVE-2023-54308: 
Linux Kernel vulnerability analysis and mitigation

CVE-2023-54308 is a use-after-free / kernel Oops vulnerability in the Linux kernel's ALSA YMFPCI sound driver. The issue arises because snd_card_new() was not replaced with snd_devm_card_new() after the removal of snd_card_ymfpci_remove() in commit c6e6bb5eab74, leaving no call to snd_card_free() on module unload. This causes a page fault (Oops) when the module is unloaded, as the kernel attempts to access already-freed memory. The vulnerability was published on December 30, 2025, and affects the Linux kernel. No CVSS score has been publicly assigned at this time (Feedly, CVE.org).

The root cause is a resource lifecycle management error (CWE-459: Incomplete Cleanup) in the ymfpci ALSA driver. When commit c6e6bb5eab74 ("ALSA: ymfpci: Allocate resources with device-managed APIs") removed snd_card_ymfpci_remove(), it eliminated the explicit snd_card_free() call but failed to switch snd_card_new() to the device-managed snd_devm_card_new(). As a result, when the ymfpci kernel module is unloaded (e.g., triggered by a userspace audio daemon like WirePlumber), the sound card structure is not properly freed, leading to a kernel page fault at try_module_get.part.0 when accessing the now-invalid memory region (Feedly). The fix replaces snd_card_new() with snd_devm_card_new() so that card cleanup is handled automatically by the device-managed framework (Kernel Git).

Successful triggering of this vulnerability causes a kernel Oops (page fault) in the Linux kernel, resulting in a denial-of-service condition on systems with YMFPCI-based sound hardware. The crash occurs in kernel mode during module unload, which can destabilize or crash the affected system. There is no evidence of confidentiality or integrity impact; the primary consequence is availability loss (Feedly).

The fix is to replace snd_card_new() with snd_devm_card_new() in the YMFPCI driver, ensuring device-managed cleanup of the sound card on module unload. Patches have been submitted to the Linux kernel stable trees (commits 255a81a89501, 95642872c466, db7d7782677f, f33fc1576757) (Kernel Git). Users should update to a patched kernel version that includes these fixes. As a workaround, avoiding unloading the snd-ymfpci module on affected systems can prevent the crash.