From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756643AbdLPBtu (ORCPT ); Fri, 15 Dec 2017 20:49:50 -0500 Received: from cloudserver094114.home.net.pl ([79.96.170.134]:63262 "EHLO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755884AbdLPBts (ORCPT ); Fri, 15 Dec 2017 20:49:48 -0500 From: "Rafael J. Wysocki" To: Colin King Cc: Len Brown , linux-acpi@vger.kernel.org, kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ACPI / CPPC: remove initial assignment of pcc_ss_data Date: Sat, 16 Dec 2017 02:49:02 +0100 Message-ID: <3514960.SrIDOzrZqR@aspire.rjw.lan> In-Reply-To: <20171208235949.15713-1-colin.king@canonical.com> References: <20171208235949.15713-1-colin.king@canonical.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Saturday, December 9, 2017 12:59:49 AM CET Colin King wrote: > From: Colin Ian King > > 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 > --- > 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) { > Applied, thanks!