Re: [PATCH v2 7/8] net/rnp add devargs runtime parsing functions

[Stephen Hemminger]

On Wed,  2 Aug 2023 08:11:05 +0000
Wenbo Cao <caowe...@mucse.com> wrote:

> +     if (strcmp(key, RNP_HW_MAC_LOOPBACK_ARG) == 0) {
> +             uint16_t *n = extra_args;
> +             *n = (uint16_t)strtoul(value, NULL, 10);
> +             if (*n == USHRT_MAX && errno == ERANGE)
> +                     return -1;

You should be using unsigned long for n here
and no cast. Otherwise a large buggy argument would not be caught.

Something like:
        if (strcmp(key, RNP_HW_MAC_LOOPBACK_ARG) == 0) {
                unsigned long n;
                uint16_t *result = extra_args;
                n = strtoul(value, NULL, 10);
                if (n > UINT16_MAX) {
                        XXXLOG("invalid loopback arg"...
                        return -1;
                }
                *result = n;