From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752998AbdKVXAd (ORCPT ); Wed, 22 Nov 2017 18:00:33 -0500 Received: from fldsmtpe03.verizon.com ([140.108.26.142]:24555 "EHLO fldsmtpe03.verizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752828AbdKVW01 (ORCPT ); Wed, 22 Nov 2017 17:26:27 -0500 From: alexander.levin@verizon.com Cc: "Edward A. James" , Guenter Roeck , alexander.levin@verizon.com X-Host: surveyor.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 4.14 16/51] hwmon: (pmbus/core) Prevent unintentional setting of page to 0xFF Thread-Topic: [PATCH AUTOSEL for 4.14 16/51] hwmon: (pmbus/core) Prevent unintentional setting of page to 0xFF Thread-Index: AQHTY+DTS/ZSY1jxUUS26VRgMIuZmg== Date: Wed, 22 Nov 2017 22:25:39 +0000 Message-ID: <20171122222526.20021-16-alexander.levin@verizon.com> References: <20171122222526.20021-1-alexander.levin@verizon.com> In-Reply-To: <20171122222526.20021-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vAMN0xRR032347 From: "Edward A. James" [ Upstream commit 6dcf2fb5e8db3704f50af1f198256cb4e2453f8b ] The pmbus core may call read/write word data functions with a page value of -1, intending to perform the operation without setting the page. However, the read/write word data functions accept only unsigned 8-bit page numbers, and therefore cannot check for negative page number to avoid setting the page. This results in setting the page number to 0xFF. This may result in errors or undefined behavior of some devices (specifically the ir35221, which allows the page to be set to 0xFF, but some subsequent operations to read registers may fail). Switch the pmbus_set_page page parameter to an integer and perform the check for negative page there. Make read/write functions consistent in accepting an integer page number parameter. Signed-off-by: Edward A. James Fixes: cbcdec6202c9 ("hwmon: (pmbus): Access word data for STATUS_WORD") Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/hwmon/pmbus/pmbus.h | 6 +++--- drivers/hwmon/pmbus/pmbus_core.c | 25 +++++++++++-------------- 2 files changed, 14 insertions(+), 17 deletions(-) diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h index 4efa2bd4f6d8..fa613bd209e3 100644 --- a/drivers/hwmon/pmbus/pmbus.h +++ b/drivers/hwmon/pmbus/pmbus.h @@ -404,9 +404,9 @@ extern const struct regulator_ops pmbus_regulator_ops; /* Function declarations */ void pmbus_clear_cache(struct i2c_client *client); -int pmbus_set_page(struct i2c_client *client, u8 page); -int pmbus_read_word_data(struct i2c_client *client, u8 page, u8 reg); -int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg, u16 word); +int pmbus_set_page(struct i2c_client *client, int page); +int pmbus_read_word_data(struct i2c_client *client, int page, u8 reg); +int pmbus_write_word_data(struct i2c_client *client, int page, u8 reg, u16 word); int pmbus_read_byte_data(struct i2c_client *client, int page, u8 reg); int pmbus_write_byte(struct i2c_client *client, int page, u8 value); int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg, diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index 302f0aef59de..52a58b8b6e1b 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -136,13 +136,13 @@ void pmbus_clear_cache(struct i2c_client *client) } EXPORT_SYMBOL_GPL(pmbus_clear_cache); -int pmbus_set_page(struct i2c_client *client, u8 page) +int pmbus_set_page(struct i2c_client *client, int page) { struct pmbus_data *data = i2c_get_clientdata(client); int rv = 0; int newpage; - if (page != data->currpage) { + if (page >= 0 && page != data->currpage) { rv = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page); newpage = i2c_smbus_read_byte_data(client, PMBUS_PAGE); if (newpage != page) @@ -158,11 +158,9 @@ int pmbus_write_byte(struct i2c_client *client, int page, u8 value) { int rv; - if (page >= 0) { - rv = pmbus_set_page(client, page); - if (rv < 0) - return rv; - } + rv = pmbus_set_page(client, page); + if (rv < 0) + return rv; return i2c_smbus_write_byte(client, value); } @@ -186,7 +184,8 @@ static int _pmbus_write_byte(struct i2c_client *client, int page, u8 value) return pmbus_write_byte(client, page, value); } -int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg, u16 word) +int pmbus_write_word_data(struct i2c_client *client, int page, u8 reg, + u16 word) { int rv; @@ -219,7 +218,7 @@ static int _pmbus_write_word_data(struct i2c_client *client, int page, int reg, return pmbus_write_word_data(client, page, reg, word); } -int pmbus_read_word_data(struct i2c_client *client, u8 page, u8 reg) +int pmbus_read_word_data(struct i2c_client *client, int page, u8 reg) { int rv; @@ -255,11 +254,9 @@ int pmbus_read_byte_data(struct i2c_client *client, int page, u8 reg) { int rv; - if (page >= 0) { - rv = pmbus_set_page(client, page); - if (rv < 0) - return rv; - } + rv = pmbus_set_page(client, page); + if (rv < 0) + return rv; return i2c_smbus_read_byte_data(client, reg); } -- 2.11.0