From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Check cpc_desc against NULL in cppc_get_perf(), so it doesn't crash down the road if cpc_desc is NULL. Fixes: 0654cf05d17b ("ACPI: CPPC: Introduce cppc_get_nominal_perf()") Reported-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Cc: 5.15+ <stable@xxxxxxxxxxxxxxx> # 5.15+ --- drivers/acpi/cppc_acpi.c | 5 +++++ 1 file changed, 5 insertions(+) Index: linux-pm/drivers/acpi/cppc_acpi.c =================================================================== --- linux-pm.orig/drivers/acpi/cppc_acpi.c +++ linux-pm/drivers/acpi/cppc_acpi.c @@ -1000,6 +1000,11 @@ static int cppc_get_perf(int cpunum, enu struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); struct cpc_register_resource *reg = &cpc_desc->cpc_regs[reg_idx]; + if (!cpc_desc) { + pr_debug("No CPC descriptor for CPU:%d\n", cpunum); + return -ENODEV; + } + if (CPC_IN_PCC(reg)) { int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); struct cppc_pcc_data *pcc_ss_data = NULL;