Re: [PATCH 1/2] HID: Intel-thc-hid: Intel-quicki2c: Use hid_safe_input_report()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] hid: intel-quicki2c: OOB memory access due to unadjusted buffer size in hid_safe_input_report()
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commit fd2fb2220e67b32415f7045570713d7e64755020
Author: Even Xu <even.xu@intel.com>

HID: Intel-thc-hid: Intel-quicki2c: Use hid_safe_input_report()

This commit replaces the deprecated hid_input_report() with
hid_safe_input_report(). It tracks the allocated size of the input buffer and
passes it along to allow hid-core to validate the reported data length against
the actual buffer size.

> diff --git a/drivers/hid/intel-thc-hid/intel-quicki2c/pci-quicki2c.c b/drivers/hid/intel-thc-hid/intel-quicki2c/pci-quicki2c.c
> index 0d2ad7bc3648a..6cf19dac8e181 100644
> --- a/drivers/hid/intel-thc-hid/intel-quicki2c/pci-quicki2c.c
> +++ b/drivers/hid/intel-thc-hid/intel-quicki2c/pci-quicki2c.c
> @@ -315,7 +315,7 @@ static int handle_input_report(struct quicki2c_device *qcdev)
>  		if (qcdev->state != QUICKI2C_ENABLED)
>  			continue;
>  
> -		quicki2c_hid_send_report(qcdev, pkt->data,
> +		quicki2c_hid_send_report(qcdev, pkt->data, qcdev->input_len,
>  					 HIDI2C_DATA_LEN(le16_to_cpu(pkt->len)));

[Severity: High]
Does this code pass the unadjusted buffer size when pkt->data is offset by 2
bytes from the start of the buffer?

The buffer qcdev->input_buf is dynamically allocated to qcdev->input_len
bytes.

Since pkt is mapped to qcdev->input_buf, pkt->data is offset by
HIDI2C_LENGTH_LEN (2 bytes) from the start of the allocation.

Passing the full qcdev->input_len overstates the remaining capacity for
pkt->data by 2 bytes.

[ ... ]

> diff --git a/drivers/hid/intel-thc-hid/intel-quicki2c/quicki2c-hid.c b/drivers/hid/intel-thc-hid/intel-quicki2c/quicki2c-hid.c
> index 8075992e8732e..1a220a50d934c 100644
> --- a/drivers/hid/intel-thc-hid/intel-quicki2c/quicki2c-hid.c
> +++ b/drivers/hid/intel-thc-hid/intel-quicki2c/quicki2c-hid.c
[ ... ]
> @@ -157,16 +157,18 @@ void quicki2c_hid_remove(struct quicki2c_device *qcdev)
>   *
>   * @qcdev: point to quicki2c device
>   * @data: point to input report data buffer
> + * @buf_size: the allocated size of the input report data buffer
>   * @data_len: the length of input report data
>   *
>   * Return: 0 on success, non zero on error.
>   */
>  int quicki2c_hid_send_report(struct quicki2c_device *qcdev,
> -			     void *data, size_t data_len)
> +			     void *data, size_t buf_size, size_t data_len)
>  {
>  	int ret;
>  
> -	ret = hid_input_report(qcdev->hid_dev, HID_INPUT_REPORT, data, data_len, 1);
> +	ret = hid_safe_input_report(qcdev->hid_dev, HID_INPUT_REPORT, data,
> +				    buf_size, data_len, 1);

[Severity: High]
Can passing this unadjusted buf_size to hid_safe_input_report() lead to an
out-of-bounds access?

If a device sends a pkt->len such that HIDI2C_DATA_LEN(pkt->len) equals
qcdev->input_len, hid_safe_input_report() will trust the data length since it
does not exceed the provided buf_size.

This would neutralize the core's bounds checks, allowing the core to read or
zero-pad 2 bytes past the end of the qcdev->input_buf allocation.

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Sashiko AI review · https://sashiko.dev/#/patchset/20260922025437.940072-1-even.xu@intel.com?part=1