CVE-2022-50322

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

rtc: msc313: Fix function prototype mismatch in msc313rtcprobe()

With clang's kernel control flow integrity (kCFI, CONFIGCFICLANG), indirect call targets are validated against the expected function pointer prototype to make sure the call target is valid to help mitigate ROP attacks. If they are not identical, there is a failure at run time, which manifests as either a kernel panic or thread getting killed.

msc313rtcprobe() was passing clkdisableunprepare() directly, which did not have matching prototypes for devmaddactionorreset()'s callback argument. Refactor to use devmclkget_enabled() instead.

This was found as a result of Clang's new -Wcast-function-type-strict flag, which is more sensitive than the simpler -Wcast-function-type, which only checks for type width mismatches.