Re: [PATCH] ACPI / CPPC: Fix negative array index read in cppc_set_perf
From: George Cherian <hidden>
Date: 2017-12-15 18:18:40
Also in:
lkml
On Thursday 14 December 2017 04:15 AM, Gustavo A. R. Silva wrote:
If pcc_ss_id is less than 0, there is a negative array index read
before verifying pcc_ss_id is not a negative value.
Fix this by removing the code that triggers this issue.
Notice that this code is already properly placed after the check
on pcc_ss_id at line 1182: pcc_ss_data = pcc_data[pcc_ss_id];
Addresses-Coverity-ID: 1426090 ("Negative array index read")
Fixes: 1ecbd7170d65 ("ACPI / CPPC: Fix KASAN global out of bounds warning")Reviewed-by: George Cherian <redacted>
quoted hunk ↗ jump to hunk
Signed-off-by: Gustavo A. R. Silva <redacted> --- 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 30e84cc..06ea474 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) {