[PATCH] ACPI / CPPC: remove initial assignment of pcc_ss_data

From: Colin King
Date: Fri Dec 08 2017 - 18:59:58 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The initialization of pcc_ss_data from pcc_data[pcc_ss_id] before
pcc_ss_id is being range checked could lead to an out-of-bounds array
read. This very same initialization is also being performed after
the range check on pcc_ss_id, so we can just remove this problematic
and also redundant assignment to fix the issue.

Detected by cppcheck:
warning: Value stored to 'pcc_ss_data' during its initialization is never
read

Fixes: commit 85b1407bf6d2 ("ACPI / CPPC: Make CPPC ACPI driver aware of PCC subspace IDs")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/acpi/cppc_acpi.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 30e84cc600ae..06ea4749ebd9 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1171,7 +1171,7 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
struct cpc_register_resource *desired_reg;
int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
- struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
+ struct cppc_pcc_data *pcc_ss_data;
int ret = 0;

if (!cpc_desc || pcc_ss_id < 0) {
--
2.14.1