2020-07-03 11:18:07

by Evgeny Novikov

Subject: [PATCH] hwmon: (aspeed-pwm-tacho) Avoid possible buffer overflow

aspeed_create_fan() reads a pwm_port value using of_property_read_u32().
If pwm_port will be more than ARRAY_SIZE(pwm_port_params), there will be
a buffer overflow in
aspeed_create_pwm_port()->aspeed_set_pwm_port_enable(). The patch fixes
the potential buffer overflow.

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

Signed-off-by: Evgeny Novikov <[email protected]>
---
drivers/hwmon/aspeed-pwm-tacho.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
index 33fb54845bf6..3d8239fd66ed 100644
--- a/drivers/hwmon/aspeed-pwm-tacho.c
+++ b/drivers/hwmon/aspeed-pwm-tacho.c
@@ -851,6 +851,8 @@ static int aspeed_create_fan(struct device *dev,
ret = of_property_read_u32(child, "reg", &pwm_port);
if (ret)
return ret;
+ if (pwm_port >= ARRAY_SIZE(pwm_port_params))
+ return -EINVAL;
aspeed_create_pwm_port(priv, (u8)pwm_port);

ret = of_property_count_u8_elems(child, "cooling-levels");
--
2.16.4

2020-07-03 22:18:19

by Guenter Roeck

Subject: Re: [PATCH] hwmon: (aspeed-pwm-tacho) Avoid possible buffer overflow

On Fri, Jul 03, 2020 at 02:15:18PM +0300, Evgeny Novikov wrote:
> aspeed_create_fan() reads a pwm_port value using of_property_read_u32().
> If pwm_port will be more than ARRAY_SIZE(pwm_port_params), there will be
> a buffer overflow in
> aspeed_create_pwm_port()->aspeed_set_pwm_port_enable(). The patch fixes
> the potential buffer overflow.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Evgeny Novikov <[email protected]>

Applied.

Thanks,
Guenter

> ---
> drivers/hwmon/aspeed-pwm-tacho.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
> index 33fb54845bf6..3d8239fd66ed 100644
> --- a/drivers/hwmon/aspeed-pwm-tacho.c
> +++ b/drivers/hwmon/aspeed-pwm-tacho.c
> @@ -851,6 +851,8 @@ static int aspeed_create_fan(struct device *dev,
> ret = of_property_read_u32(child, "reg", &pwm_port);
> if (ret)
> return ret;
> + if (pwm_port >= ARRAY_SIZE(pwm_port_params))
> + return -EINVAL;
> aspeed_create_pwm_port(priv, (u8)pwm_port);
>
> ret = of_property_count_u8_elems(child, "cooling-levels");