Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752580AbdLMWpr (ORCPT ); Wed, 13 Dec 2017 17:45:47 -0500 Received: from gateway31.websitewelcome.com ([192.185.143.4]:25421 "EHLO gateway31.websitewelcome.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751090AbdLMWpp (ORCPT ); Wed, 13 Dec 2017 17:45:45 -0500 Date: Wed, 13 Dec 2017 16:45:41 -0600 From: "Gustavo A. R. Silva" To: "Rafael J. Wysocki" , Len Brown , George Cherian Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" Subject: [PATCH] ACPI / CPPC: Fix negative array index read in cppc_set_perf Message-ID: <20171213224541.GA31477@embeddedor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.24 (2015-08-30) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - gator4166.hostgator.com X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - embeddedor.com X-BWhitelist: no X-Source-IP: 189.175.3.118 X-Source-L: No X-Exim-ID: 1ePFmZ-000fqj-W3 X-Source: X-Source-Args: X-Source-Dir: X-Source-Sender: (embeddedor) [189.175.3.118]:45836 X-Source-Auth: garsilva@embeddedor.com X-Email-Count: 5 X-Source-Cap: Z3V6aWRpbmU7Z3V6aWRpbmU7Z2F0b3I0MTY2Lmhvc3RnYXRvci5jb20= X-Local-Domain: yes Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1145 Lines: 30 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") Signed-off-by: Gustavo A. R. Silva --- 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) { -- 2.7.4