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 S2DPHYSADDRLOW and S2DPHYSADDRHIGH 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.