Re: [PATCH 2/3] watchdog: ziirave_wdt: check record length in ziirave_firm_verify()

[Guenter Roeck <linux@roeck-us.net>]

On 5/28/25 13:22, Dan Carpenter wrote:
> The "rec->len" value comes from the firmware.  We generally do
> trust firmware, but it's always better to double check.  If
> the length value is too large it would lead to memory corruption
> when we set "data[i] = ret;"
> 
> Fixes: 217209db0204 ("watchdog: ziirave_wdt: Add support to upload the firmware.")
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Reviewed-by: Guenetr Roeck <linux@roeck-us.net>

> ---
>   drivers/watchdog/ziirave_wdt.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/watchdog/ziirave_wdt.c b/drivers/watchdog/ziirave_wdt.c
> index fcc1ba02e75b..5c6e3fa001d8 100644
> --- a/drivers/watchdog/ziirave_wdt.c
> +++ b/drivers/watchdog/ziirave_wdt.c
> @@ -302,6 +302,9 @@ static int ziirave_firm_verify(struct watchdog_device *wdd,
>   		const u16 len = be16_to_cpu(rec->len);
>   		const u32 addr = be32_to_cpu(rec->addr);
>   
> +		if (len > sizeof(data))
> +			return -EINVAL;
> +
>   		if (ziirave_firm_addr_readonly(addr))
>   			continue;
>