cpufreq: apple-soc: Fix null-ptr-deref in apple_soc_cpufreq_get_rate()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: cpufreq: apple-soc: Fix null-ptr-deref in apple_soc_cpufreq_get_rate() cpufreq_cpu_get_raw() can return NULL when the target CPU is not present in the policy->cpus mask. apple_soc_cpufreq_get_rate() does not check for this case, which results in a NULL pointer dereference.

References

• https://git.kernel.org/stable/c/1053dcf8a504d4933bb3f73df22bc363298d194b
• https://git.kernel.org/stable/c/fbdba5f37413dbc09d82ad7235e5b7a2fb8e0f75
• https://git.kernel.org/stable/c/01e86ea22610d98ae6141e428019a6916e79f725
• https://git.kernel.org/stable/c/9992649f6786921873a9b89dafa5e04d8c5fef2b