diff options
| author | Nadezda Lutovinova <lutovinova@ispras.ru> | 2021-09-21 17:51:53 +0200 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2021-10-02 14:14:11 +0200 |
| commit | dd4d747ef05addab887dc8ff0d6ab9860bbcd783 (patch) | |
| tree | 95d49c4c5a72dd1612fce3c162e8e90a2937c0c8 /drivers/hwmon/w83793.c | |
| parent | hwmon: (w83792d) Fix NULL pointer dereference by removing unnecessary structu... (diff) | |
| download | linux-dd4d747ef05addab887dc8ff0d6ab9860bbcd783.tar.xz linux-dd4d747ef05addab887dc8ff0d6ab9860bbcd783.zip | |
hwmon: (w83793) Fix NULL pointer dereference by removing unnecessary structure field
If driver read tmp 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)
Also lm75[] does not serve a purpose anymore after switching to
devm_i2c_new_dummy_device() in w83791d_detect_subclients().
The patch fixes possible NULL pointer dereference by removing lm75[].
Found by Linux Driver Verification project (linuxtesting.org).
Cc: stable@vger.kernel.org
Signed-off-by: Nadezda Lutovinova <lutovinova@ispras.ru>
Link: https://lore.kernel.org/r/20210921155153.28098-3-lutovinova@ispras.ru
[groeck: Dropped unnecessary continuation lines, fixed multi-line alignments]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon/w83793.c')
| -rw-r--r-- | drivers/hwmon/w83793.c | 26 |
1 files changed, 11 insertions, 15 deletions
diff --git a/drivers/hwmon/w83793.c b/drivers/hwmon/w83793.c index e7d0484eabe4..1d2854de1cfc 100644 --- a/drivers/hwmon/w83793.c +++ b/drivers/hwmon/w83793.c @@ -202,7 +202,6 @@ static inline s8 TEMP_TO_REG(long val, s8 min, s8 max) } struct w83793_data { - struct i2c_client *lm75[2]; struct device *hwmon_dev; struct mutex update_lock; char valid; /* !=0 if following fields are valid */ @@ -1566,7 +1565,6 @@ w83793_detect_subclients(struct i2c_client *client) int address = client->addr; u8 tmp; struct i2c_adapter *adapter = client->adapter; - struct w83793_data *data = i2c_get_clientdata(client); id = i2c_adapter_id(adapter); if (force_subclients[0] == id && force_subclients[1] == address) { @@ -1586,21 +1584,19 @@ w83793_detect_subclients(struct i2c_client *client) } tmp = w83793_read_value(client, W83793_REG_I2C_SUBADDR); - if (!(tmp & 0x08)) - data->lm75[0] = devm_i2c_new_dummy_device(&client->dev, adapter, - 0x48 + (tmp & 0x7)); - if (!(tmp & 0x80)) { - if (!IS_ERR(data->lm75[0]) - && ((tmp & 0x7) == ((tmp >> 4) & 0x7))) { - dev_err(&client->dev, - "duplicate addresses 0x%x, " - "use force_subclients\n", data->lm75[0]->addr); - return -ENODEV; - } - data->lm75[1] = devm_i2c_new_dummy_device(&client->dev, adapter, - 0x48 + ((tmp >> 4) & 0x7)); + + if (!(tmp & 0x88) && (tmp & 0x7) == ((tmp >> 4) & 0x7)) { + dev_err(&client->dev, + "duplicate addresses 0x%x, use force_subclient\n", 0x48 + (tmp & 0x7)); + return -ENODEV; } + if (!(tmp & 0x08)) + devm_i2c_new_dummy_device(&client->dev, adapter, 0x48 + (tmp & 0x7)); + + if (!(tmp & 0x80)) + devm_i2c_new_dummy_device(&client->dev, adapter, 0x48 + ((tmp >> 4) & 0x7)); + return 0; } |