Re: [PATCH] nfc: fdp: add null check of devm_kmalloc_array in fdp_nci_i2c_read_device_properties

[Simon Horman <simon.horman@corigine.com>]

On Sun, Feb 26, 2023 at 05:59:33PM +0800, Kang Chen wrote:
> devm_kmalloc_array may fails, *fw_vsc_cfg might be null and cause
> out-of-bounds write in device_property_read_u8_array later.
> 
> Signed-off-by: Kang Chen <void0red@gmail.com>

I'm not sure if this is a bug-fix (for stable).
But if so, I think the following is the appropriate fixes tag.

Fixes: a06347c04c13 ("NFC: Add Intel Fields Peak NFC solution driver")

> ---
>  drivers/nfc/fdp/i2c.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/nfc/fdp/i2c.c b/drivers/nfc/fdp/i2c.c
> index 2d53e0f88..d95d20efa 100644
> --- a/drivers/nfc/fdp/i2c.c
> +++ b/drivers/nfc/fdp/i2c.c
> @@ -247,6 +247,9 @@ static void fdp_nci_i2c_read_device_properties(struct device *dev,
>  					   len, sizeof(**fw_vsc_cfg),
>  					   GFP_KERNEL);
>  
> +		if (!*fw_vsc_cfg)
> +			goto vsc_read_err;

This leads to:

	dev_dbg(dev, "FW vendor specific commands not present\n");

Which seems a little misleading for this error condition.

> +
>  		r = device_property_read_u8_array(dev, FDP_DP_FW_VSC_CFG_NAME,
>  						  *fw_vsc_cfg, len);
>  
> -- 
> 2.34.1
>