In the Linux kernel, the following vulnerability has been resolved:

ASoC: fsl_micfil: balance mclk enable/disable

hw_params() enables mclk unconditionally and hw_free() disables it
unconditionally, but the PCM core does not guarantee 1:1 pairing:
hw_free() can run without hw_params(), and hw_params() can be called
multiple times from the SETUP state. This triggers an "already
disabled" WARN() in the first case and leaks an enable reference in
the second, leaving the clock ungateable.

Guard both sides with the existing mclk_flag, as fsl_sai.c does with
mclk_streams.