Re: [PATCH] hwmon: (hih6130) Replace sprintf() with sysfs_emit()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] The driver performs I2C transfers using a stack-allocated buffer, violating the DMA API and potentially causing memory corruption.
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commit 8d977f465d31017a7624b9759009bb470f1a65cc
Author: Massinissa Ghoul <massigh680@gmail.com>

hwmon: (hih6130) Replace sprintf() with sysfs_emit()

Use sysfs_emit() instead of sprintf() in the sysfs show functions
hih6130_temperature_show() and hih6130_humidity_show() to use the
preferred kernel interface for writing to sysfs buffers.

> diff --git a/drivers/hwmon/hih6130.c b/drivers/hwmon/hih6130.c
> index 7984be1e706d5..6a79aab5d1285 100644
> --- a/drivers/hwmon/hih6130.c
> +++ b/drivers/hwmon/hih6130.c
> @@ -168,7 +168,7 @@ static ssize_t hih6130_temperature_show(struct device *dev,
>  	ret = hih6130_update_measurements(dev);
>  	if (ret < 0)
>  		return ret;

[Severity: High]
This isn't a bug introduced by this patch, but looking at the call to
hih6130_update_measurements(), is there a DMA-safety issue with how it
performs I2C transfers?

Inside hih6130_update_measurements(), a non-DMA-safe buffer is allocated
on the execution stack:

    unsigned char tmp[4];
    struct i2c_msg msgs[1] = {
        {
            .addr = client->addr,
            .flags = I2C_M_RD,
            .len = 4,
            .buf = tmp,
        }
    };

This stack buffer is then passed directly into I2C functions that may
initiate a DMA operation:

    ret = i2c_master_send(client, tmp, hih6130->write_length);
    ...
    ret = i2c_transfer(client->adapter, msgs, 1);

Could this lead to memory corruption or kernel panics if the underlying
I2C controller driver attempts to DMA map this stack memory?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260907-hwmon-hih6130-sysfs-emit-v1-1-a1adb5245d0f@gmail.com?part=1