From patchwork Mon Jun 18 17:56:37 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Hutchings X-Patchwork-Id: 10472469 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id E9D386032A for ; Mon, 18 Jun 2018 17:56:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DE94628BA3 for ; Mon, 18 Jun 2018 17:56:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D321328BAF; Mon, 18 Jun 2018 17:56:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0CCD228BA3 for ; Mon, 18 Jun 2018 17:56:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935428AbeFRR4n (ORCPT ); Mon, 18 Jun 2018 13:56:43 -0400 Received: from imap1.codethink.co.uk ([176.9.8.82]:41781 "EHLO imap1.codethink.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935544AbeFRR4n (ORCPT ); Mon, 18 Jun 2018 13:56:43 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126] helo=xylophone.i.decadent.org.uk) by imap1.codethink.co.uk with esmtpsa (Exim 4.84_2 #1 (Debian)) id 1fUyOP-0003J8-4e; Mon, 18 Jun 2018 18:56:41 +0100 Date: Mon, 18 Jun 2018 18:56:37 +0100 From: Ben Hutchings To: Dmitry Torokhov Cc: linux-input@vger.kernel.org, Benjamin Tissoires , stable@vger.kernel.org Subject: [PATCH] Input elan_i2c_smbus - Fix more potential stack buffer overflows Message-ID: <20180618175117.yj6zxpir6whtvisb@xylophone.i.decadent.org.uk> MIME-Version: 1.0 Content-Disposition: inline User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Commit 40f7090bb1b4 ("Input: elan_i2c_smbus - fix corrupted stack") fixed most of the functions using i2c_smbus_read_block_data() to allocate a buffer with the maximum block size. However three functions were left unchanged: * In elan_smbus_initialize(), increase the buffer size in the same way. * In elan_smbus_calibrate_result(), the buffer is provided by the caller (calibrate_store()), so introduce a bounce buffer. Also name the result buffer size. * In elan_smbus_get_report(), the buffer is provided by the caller but happens to be the right length. Add a compile-time assertion to ensure this remains the case. Cc: # 3.19+ Signed-off-by: Ben Hutchings Reviewed-by: Benjamin Tissoires --- This is compile-tested only. Ben. drivers/input/mouse/elan_i2c.h | 2 ++ drivers/input/mouse/elan_i2c_core.c | 2 +- drivers/input/mouse/elan_i2c_smbus.c | 10 ++++++++-- 3 files changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/input/mouse/elan_i2c.h b/drivers/input/mouse/elan_i2c.h index 599544c1a91c..243e0fa6e3e3 100644 --- a/drivers/input/mouse/elan_i2c.h +++ b/drivers/input/mouse/elan_i2c.h @@ -27,6 +27,8 @@ #define ETP_DISABLE_POWER 0x0001 #define ETP_PRESSURE_OFFSET 25 +#define ETP_CALIBRATE_MAX_LEN 3 + /* IAP Firmware handling */ #define ETP_PRODUCT_ID_FORMAT_STRING "%d.0" #define ETP_FW_NAME "elan_i2c_" ETP_PRODUCT_ID_FORMAT_STRING ".bin" diff --git a/drivers/input/mouse/elan_i2c_core.c b/drivers/input/mouse/elan_i2c_core.c index 75e757520ef0..d5f74dd7e23b 100644 --- a/drivers/input/mouse/elan_i2c_core.c +++ b/drivers/input/mouse/elan_i2c_core.c @@ -610,7 +610,7 @@ static ssize_t calibrate_store(struct device *dev, int tries = 20; int retval; int error; - u8 val[3]; + u8 val[ETP_CALIBRATE_MAX_LEN]; retval = mutex_lock_interruptible(&data->sysfs_mutex); if (retval) diff --git a/drivers/input/mouse/elan_i2c_smbus.c b/drivers/input/mouse/elan_i2c_smbus.c index cfcb32559925..c060d270bc4d 100644 --- a/drivers/input/mouse/elan_i2c_smbus.c +++ b/drivers/input/mouse/elan_i2c_smbus.c @@ -56,7 +56,7 @@ static int elan_smbus_initialize(struct i2c_client *client) { u8 check[ETP_SMBUS_HELLOPACKET_LEN] = { 0x55, 0x55, 0x55, 0x55, 0x55 }; - u8 values[ETP_SMBUS_HELLOPACKET_LEN] = { 0, 0, 0, 0, 0 }; + u8 values[I2C_SMBUS_BLOCK_MAX] = {0}; int len, error; /* Get hello packet */ @@ -117,12 +117,16 @@ static int elan_smbus_calibrate(struct i2c_client *client) static int elan_smbus_calibrate_result(struct i2c_client *client, u8 *val) { int error; + u8 buf[I2C_SMBUS_BLOCK_MAX] = {0}; + + BUILD_BUG_ON(ETP_CALIBRATE_MAX_LEN > sizeof(buf)); error = i2c_smbus_read_block_data(client, - ETP_SMBUS_CALIBRATE_QUERY, val); + ETP_SMBUS_CALIBRATE_QUERY, buf); if (error < 0) return error; + memcpy(val, buf, ETP_CALIBRATE_MAX_LEN); return 0; } @@ -472,6 +476,8 @@ static int elan_smbus_get_report(struct i2c_client *client, u8 *report) { int len; + BUILD_BUG_ON(I2C_SMBUS_BLOCK_MAX > ETP_SMBUS_REPORT_LEN); + len = i2c_smbus_read_block_data(client, ETP_SMBUS_PACKET_QUERY, &report[ETP_SMBUS_REPORT_OFFSET]);