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

platform/x86/amd/pmc: Detect when STB is not available

Loading the amd_pmc module as:

    amd_pmc enable_stb=1

...can result in the following messages in the kernel ring buffer:

    amd_pmc AMDI0009:00: SMU cmd failed. err: 0xff
    ioremap on RAM at 0x0000000000000000 - 0x0000000000ffffff
    WARNING: CPU: 10 PID: 2151 at arch/x86/mm/ioremap.c:217 __ioremap_caller+0x2cd/0x340

Further debugging reveals that this occurs when the requests for
S2D_PHYS_ADDR_LOW and S2D_PHYS_ADDR_HIGH return a value of 0,
indicating that the STB is inaccessible. To prevent the ioremap
warning and provide clarity to the user, handle the invalid address
and display an error message.

kernel.org https://git.kernel.org/stable/c/67ff30e24a0466bdd5be1d0b84385ec3c85fdacd [No types assigned]

kernel.org https://git.kernel.org/stable/c/7a3ed3f125292bc3398e04d10108124250892e3f [No types assigned]

kernel.org https://git.kernel.org/stable/c/a50863dd1f92d43c975ab2ecc3476617fe98a66e [No types assigned]

kernel.org https://git.kernel.org/stable/c/bceec87a73804bb4c33b9a6c96e2d27cd893a801 [No types assigned]