Re: [PATCH v2] Input: lpc32xx-keys - reject matrices bigger than the hardware has

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Input: lpc32xx-keys: undeclared LPC32XX_MAX_MATRIX_SIZE in lpc32xx_parse_dt()
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commit ae2a42c5ed13c05919e7d77f5f4978ad957e69a7
Author: Guanglei Zhu <zhugl3@xiaopeng.com>

Input: lpc32xx-keys - reject matrices bigger than the hardware has

This commit adds an upper-bound check in lpc32xx_parse_dt() to reject device
tree keypad matrices larger than LPC32XX_MAX_MATRIX_SIZE, preventing
out-of-bounds accesses to the lastkeystates array.

> diff --git a/drivers/input/keyboard/lpc32xx-keys.c b/drivers/input/keyboard/lpc32xx-keys.c
> index 285d5c32fe70f..b7cd968311cd2 100644
> --- a/drivers/input/keyboard/lpc32xx-keys.c
> +++ b/drivers/input/keyboard/lpc32xx-keys.c
> @@ -65,7 +65,7 @@ struct lpc32xx_kscan_drv {
>  	unsigned int row_shift;
>  	unsigned short *keymap;	/* Pointer to key map for the scan matrix */
>  
> -	u8 lastkeystates[8];
> +	u8 lastkeystates[LPC32XX_MAX_MATRIX_SIZE];
>  };
>  
>  static void lpc32xx_mod_states(struct lpc32xx_kscan_drv *kscandat, int col)
> @@ -141,6 +141,12 @@ static int lpc32xx_parse_dt(struct device *dev,
>  		dev_err(dev, "rows and columns must be equal!\n");
>  		return -EINVAL;
>  	}
> +	if (rows > LPC32XX_MAX_MATRIX_SIZE) {
> +		dev_err(dev, "rows and columns must be at most %d!\n",
> +			LPC32XX_MAX_MATRIX_SIZE);
> +		return -EINVAL;
> +	}

[Severity: Low]
Does this break the build when CONFIG_KEYBOARD_LPC32XX is enabled? Both
struct lpc32xx_kscan_drv and lpc32xx_parse_dt() in
drivers/input/keyboard/lpc32xx-keys.c reference LPC32XX_MAX_MATRIX_SIZE,
which is not defined anywhere in the file or included headers. Was a
#define LPC32XX_MAX_MATRIX_SIZE 8 macro definition omitted from the patch?

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Sashiko AI review · https://sashiko.dev/#/patchset/20261104030709.791761-1-zhugl3@xiaopeng.com?part=1