In the Linux kernel ASoC subsystem the fsl_micfil driver contains a logic flaw where the hardware parameters routine enables the master clock (mclk) without checking its current status, and the corresponding free routine disables it unconditionally. Because these two callbacks are not guaranteed to be called in a 1:1 sequence, a call to hw_free() can occur without a preceding hw_params() and an hw_params() can be invoked repeatedly during the SETUP state. The first scenario triggers a WARN() as the clock is already disabled, while the second scenario leaks an enable reference, causing the clock to remain enabled and ungateable. This resource leak can prevent proper shutdown of the audio hardware and may degrade system stability, effectively serving as a denial‑of‑service vector.

Affected systems include Linux kernel 7.3 rc1 and rc2 releases that incorporate the fsl_micfil ASoC driver, as well as any prior kernel versions containing this driver before the fix.

The EPSS score for this issue is < 1%, and the vulnerability is not listed in the CISA KEV catalog, suggesting that no public exploit is known. The CVSS score of 7.8 indicates a high severity. Though the flaw requires code paths within the kernel and no remote exploitation vector is documented, the bug can be triggered locally by applications that exercise the PCM audio subsystem and could lead to a steady resource leak of the master clock, causing intermittent or permanent loss of audio capability. The likely attack vector is local exploitation through the PCM audio subsystem, inferred from the description since no explicit vector is listed.