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From: Nadezda Lutovinova <lutovinova@ispras.ru>
To: Marc Hulsman <m.hulsman@tudelft.nl>
Cc: Nadezda Lutovinova <lutovinova@ispras.ru>,
	Jean Delvare <jdelvare@suse.com>,
	Guenter Roeck <linux@roeck-us.net>,
	Rudolf Marek <r.marek@assembler.cz>,
	linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org,
	ldv-project@linuxtesting.org
Subject: [PATCH] hwmon: Correct the error handling in w83793.c, w83791d.c, w83792d.c
Date: Wed, 11 Aug 2021 19:15:15 +0300	[thread overview]
Message-ID: <20210811161515.17842-2-lutovinova@ispras.ru> (raw)
In-Reply-To: <20210811161515.17842-1-lutovinova@ispras.ru>

If driver read tmp (or val) value sufficient for 
(tmp & 0x08) && (!(tmp & 0x80)) && ((tmp & 0x7) == ((tmp >> 4) & 0x7))
from device then Null pointer dereference occurs. 
(It is possible if tmp = 0b0xyz1xyz, where same literals mean same numbers)

The patch adds checking if data->lm75[0] is NULL.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Nadezda Lutovinova <lutovinova@ispras.ru>
---
 drivers/hwmon/w83791d.c | 2 +-
 drivers/hwmon/w83792d.c | 2 +-
 drivers/hwmon/w83793.c  | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hwmon/w83791d.c b/drivers/hwmon/w83791d.c
index 37b25a1474c4..8b30bbfafaa7 100644
--- a/drivers/hwmon/w83791d.c
+++ b/drivers/hwmon/w83791d.c
@@ -1284,7 +1284,7 @@ static int w83791d_detect_subclients(struct i2c_client *client)
 		data->lm75[0] = devm_i2c_new_dummy_device(&client->dev, adapter,
 							  0x48 + (val & 0x7));
 	if (!(val & 0x80)) {
-		if (!IS_ERR(data->lm75[0]) &&
+		if (!IS_ERR_OR_NULL(data->lm75[0]) &&
 				((val & 0x7) == ((val >> 4) & 0x7))) {
 			dev_err(&client->dev,
 				"duplicate addresses 0x%x, "
diff --git a/drivers/hwmon/w83792d.c b/drivers/hwmon/w83792d.c
index abd5c3a722b9..85ae12d950e1 100644
--- a/drivers/hwmon/w83792d.c
+++ b/drivers/hwmon/w83792d.c
@@ -950,7 +950,7 @@ w83792d_detect_subclients(struct i2c_client *new_client)
 		data->lm75[0] = devm_i2c_new_dummy_device(&new_client->dev, adapter,
 							  0x48 + (val & 0x7));
 	if (!(val & 0x80)) {
-		if (!IS_ERR(data->lm75[0]) &&
+		if (!IS_ERR_OR_NULL(data->lm75[0]) &&
 			((val & 0x7) == ((val >> 4) & 0x7))) {
 			dev_err(&new_client->dev,
 				"duplicate addresses 0x%x, use force_subclient\n",
diff --git a/drivers/hwmon/w83793.c b/drivers/hwmon/w83793.c
index e7d0484eabe4..9d8c44e2fa6e 100644
--- a/drivers/hwmon/w83793.c
+++ b/drivers/hwmon/w83793.c
@@ -1590,7 +1590,7 @@ w83793_detect_subclients(struct i2c_client *client)
 		data->lm75[0] = devm_i2c_new_dummy_device(&client->dev, adapter,
 							  0x48 + (tmp & 0x7));
 	if (!(tmp & 0x80)) {
-		if (!IS_ERR(data->lm75[0])
+		if (!IS_ERR_OR_NULL(data->lm75[0])
 		    && ((tmp & 0x7) == ((tmp >> 4) & 0x7))) {
 			dev_err(&client->dev,
 				"duplicate addresses 0x%x, "
-- 
2.17.1


  reply	other threads:[~2021-08-11 16:15 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-11 16:15 hwmon: Error handling in w83793.c, w83791d.c, w83792d.c Nadezda Lutovinova
2021-08-11 16:15 ` Nadezda Lutovinova [this message]
2021-08-11 18:18   ` [PATCH] hwmon: Correct the error " Guenter Roeck
2021-09-21 15:51     ` [PATCH v2 1/3] hwmon: (w83791d) Fix NULL pointer dereference by removing unnecessary structure field Nadezda Lutovinova
2021-10-02 12:07       ` Guenter Roeck
2021-09-21 15:51     ` [PATCH v2 2/3] hwmon: (w83792d) " Nadezda Lutovinova
2021-10-02 12:12       ` Guenter Roeck
2021-09-21 15:51     ` [PATCH v2 3/3] hwmon: (w83793) " Nadezda Lutovinova
2021-10-02 12:15       ` Guenter Roeck
2021-08-11 17:51 ` hwmon: Error handling in w83793.c, w83791d.c, w83792d.c Guenter Roeck
2021-08-11 18:19   ` Guenter Roeck

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