Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753395AbdHJQqg (ORCPT ); Thu, 10 Aug 2017 12:46:36 -0400 Received: from bran.ispras.ru ([83.149.199.196]:18169 "EHLO smtp.ispras.ru" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752697AbdHJQqf (ORCPT ); Thu, 10 Aug 2017 12:46:35 -0400 From: Anton Vasilyev To: Guenter Roeck Cc: Anton Vasilyev , Jean Delvare , linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org Subject: [PATCH v2] hwmon:(stts751) buffer overread on wrong chip configuration Date: Thu, 10 Aug 2017 19:46:32 +0300 Message-Id: <1502383592-14389-1-git-send-email-vasilyev@ispras.ru> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1063 Lines: 33 If stts751 hw by some reason reports conversion rate bigger then 9: ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE); then dereference stts751_intervals[priv->interval] leads to buffer overread. The path adds sanity check for value stored on chip. Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Anton Vasilyev --- v2: Fixed Guenter's remark about comparison --- drivers/hwmon/stts751.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/hwmon/stts751.c b/drivers/hwmon/stts751.c index d56251d..3f940fb 100644 --- a/drivers/hwmon/stts751.c +++ b/drivers/hwmon/stts751.c @@ -718,6 +718,10 @@ static int stts751_read_chip_config(struct stts751_priv *priv) ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE); if (ret < 0) return ret; + if (ret >= ARRAY_SIZE(stts751_intervals)) { + dev_err(priv->dev, "Unrecognized conversion rate 0x%x\n", ret); + return -ENODEV; + } priv->interval = ret; ret = stts751_read_reg16(priv, &priv->event_max, -- 2.7.4