Re: [PATCH v1 net-next 1/7] neighbour: Make neigh_valid_get_req() return ndmsg.

[Simon Horman <horms@kernel.org>]

On Tue, Apr 15, 2025 at 05:41:24PM -0700, Kuniyuki Iwashima wrote:
> neigh_get() passes 4 local variable pointers to neigh_valid_get_req().
> 
> If it returns a pointer of struct ndmsg, we do not need to pass two
> of them.
> 
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>

...

> @@ -2893,17 +2892,19 @@ static int neigh_valid_get_req(const struct nlmsghdr *nlh,
>  		case NDA_DST:
>  			if (nla_len(tb[i]) != (int)(*tbl)->key_len) {
>  				NL_SET_ERR_MSG(extack, "Invalid network address in neighbor get request");
> -				return -EINVAL;

Hi Iwashima-san,

I think you need the following here:

				err = -EINVAL;

> +				goto err;
>  			}
>  			*dst = nla_data(tb[i]);
>  			break;
>  		default:
>  			NL_SET_ERR_MSG(extack, "Unsupported attribute in neighbor get request");
> -			return -EINVAL;

And here.

Flagged by Smatch as:

  .../neighbour.c:2907 neigh_valid_get_req() warn: passing zero to 'ERR_PTR'

> +			goto err;
>  		}
>  	}
>  
> -	return 0;
> +	return ndm;
> +err:
> +	return ERR_PTR(err);
>  }
>  
>  static inline size_t neigh_nlmsg_size(void)

...