From e0b8e1ae8306ab8d8e56d8bbc32327eba5f12a42 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 18 Nov 2021 14:37:38 +0100 Subject: [PATCH] ACPI: CPPC: Add NULL pointer check to cppc_get_perf() commit 935dff305da2be7957a5ce8f07f45d6c4c1c6984 upstream. 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 Signed-off-by: Rafael J. Wysocki Cc: 5.15+ # 5.15+ Tested-by: Kai-Heng Feng Signed-off-by: Greg Kroah-Hartman --- drivers/acpi/cppc_acpi.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index bd48210..3fbb17e 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1011,7 +1011,14 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val) static int cppc_get_perf(int cpunum, enum cppc_regs reg_idx, u64 *perf) { struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum); - struct cpc_register_resource *reg = &cpc_desc->cpc_regs[reg_idx]; + struct cpc_register_resource *reg; + + if (!cpc_desc) { + pr_debug("No CPC descriptor for CPU:%d\n", cpunum); + return -ENODEV; + } + + reg = &cpc_desc->cpc_regs[reg_idx]; if (CPC_IN_PCC(reg)) { int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); -- 2.7.4