4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Guenter Roeck linux@roeck-us.net
[ Upstream commit c793279c77035053e67937f5743c6ebfc303e7c5 ]
Not all fans have a fan pulse register. This can result in reading beyond the end of REG_FAN_PULSES and FAN_PULSE_SHIFT arrays, and was reported by smatch as possible error.
1672 for (i = 0; i < ARRAY_SIZE(data->rpm); i++) { ^^^^^^^^^^^^^^^^^^^^^^^^ This is a 7 element array. ... 1685 data->fan_pulses[i] = 1686 (nct6775_read_value(data, data->REG_FAN_PULSES[i]) 1687 >> data->FAN_PULSE_SHIFT[i]) & 0x03; ^^^^^^^^^^^^^^^^^^^^^^^^ FAN_PULSE_SHIFT is either 5 or 6 elements.
To fix the problem, we have to ensure that all REG_FAN_PULSES and FAN_PULSE_SHIFT have the appropriate length, and that REG_FAN_PULSES is only read if the register actually exists.
Fixes: 6c009501ff200 ("hwmon: (nct6775) Add support for NCT6102D/6106D") Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/hwmon/nct6775.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-)
--- a/drivers/hwmon/nct6775.c +++ b/drivers/hwmon/nct6775.c @@ -299,8 +299,9 @@ static const u16 NCT6775_REG_PWM_READ[]
static const u16 NCT6775_REG_FAN[] = { 0x630, 0x632, 0x634, 0x636, 0x638 }; static const u16 NCT6775_REG_FAN_MIN[] = { 0x3b, 0x3c, 0x3d }; -static const u16 NCT6775_REG_FAN_PULSES[] = { 0x641, 0x642, 0x643, 0x644, 0 }; -static const u16 NCT6775_FAN_PULSE_SHIFT[] = { 0, 0, 0, 0, 0, 0 }; +static const u16 NCT6775_REG_FAN_PULSES[NUM_FAN] = { + 0x641, 0x642, 0x643, 0x644 }; +static const u16 NCT6775_FAN_PULSE_SHIFT[NUM_FAN] = { };
static const u16 NCT6775_REG_TEMP[] = { 0x27, 0x150, 0x250, 0x62b, 0x62c, 0x62d }; @@ -425,8 +426,8 @@ static const u8 NCT6776_PWM_MODE_MASK[]
static const u16 NCT6776_REG_FAN_MIN[] = { 0x63a, 0x63c, 0x63e, 0x640, 0x642, 0x64a, 0x64c }; -static const u16 NCT6776_REG_FAN_PULSES[] = { - 0x644, 0x645, 0x646, 0x647, 0x648, 0x649, 0 }; +static const u16 NCT6776_REG_FAN_PULSES[NUM_FAN] = { + 0x644, 0x645, 0x646, 0x647, 0x648, 0x649 };
static const u16 NCT6776_REG_WEIGHT_DUTY_BASE[] = { 0x13e, 0x23e, 0x33e, 0x83e, 0x93e, 0xa3e }; @@ -502,8 +503,8 @@ static const s8 NCT6779_BEEP_BITS[] = {
static const u16 NCT6779_REG_FAN[] = { 0x4b0, 0x4b2, 0x4b4, 0x4b6, 0x4b8, 0x4ba, 0x660 }; -static const u16 NCT6779_REG_FAN_PULSES[] = { - 0x644, 0x645, 0x646, 0x647, 0x648, 0x649, 0 }; +static const u16 NCT6779_REG_FAN_PULSES[NUM_FAN] = { + 0x644, 0x645, 0x646, 0x647, 0x648, 0x649 };
static const u16 NCT6779_REG_CRITICAL_PWM_ENABLE[] = { 0x136, 0x236, 0x336, 0x836, 0x936, 0xa36, 0xb36 }; @@ -779,8 +780,8 @@ static const u16 NCT6106_REG_TEMP_CONFIG
static const u16 NCT6106_REG_FAN[] = { 0x20, 0x22, 0x24 }; static const u16 NCT6106_REG_FAN_MIN[] = { 0xe0, 0xe2, 0xe4 }; -static const u16 NCT6106_REG_FAN_PULSES[] = { 0xf6, 0xf6, 0xf6, 0, 0 }; -static const u16 NCT6106_FAN_PULSE_SHIFT[] = { 0, 2, 4, 0, 0 }; +static const u16 NCT6106_REG_FAN_PULSES[] = { 0xf6, 0xf6, 0xf6 }; +static const u16 NCT6106_FAN_PULSE_SHIFT[] = { 0, 2, 4 };
static const u8 NCT6106_REG_PWM_MODE[] = { 0xf3, 0xf3, 0xf3 }; static const u8 NCT6106_PWM_MODE_MASK[] = { 0x01, 0x02, 0x04 }; @@ -1682,9 +1683,13 @@ static struct nct6775_data *nct6775_upda if (data->has_fan_min & BIT(i)) data->fan_min[i] = nct6775_read_value(data, data->REG_FAN_MIN[i]); - data->fan_pulses[i] = - (nct6775_read_value(data, data->REG_FAN_PULSES[i]) - >> data->FAN_PULSE_SHIFT[i]) & 0x03; + + if (data->REG_FAN_PULSES[i]) { + data->fan_pulses[i] = + (nct6775_read_value(data, + data->REG_FAN_PULSES[i]) + >> data->FAN_PULSE_SHIFT[i]) & 0x03; + }
nct6775_select_fan_div(dev, data, i, reg); }