Re: [PATCH v9 18/23] fwd_rule: Fix static checkers warnings in fwd_rule_add()

[Laurent Vivier <lvivier@redhat.com>]

On 5/6/26 11:22, Stefano Brivio wrote:
> The new checks are actually sufficient but not enough for Coverity
> Scan. Now that fwd->sock_count and new->last are affected or supplied
> by clients, we need explicit (albeit redundant) checks on them.
> 
> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Reviewed-by: Laurent Vivier <lvivier@redhat.com>

> ---
>   fwd_rule.c | 11 +++++++++++
>   1 file changed, 11 insertions(+)
> 
> diff --git a/fwd_rule.c b/fwd_rule.c
> index b55e4df..200f4b5 100644
> --- a/fwd_rule.c
> +++ b/fwd_rule.c
> @@ -271,13 +271,24 @@ int fwd_rule_add(struct fwd_table *fwd, const struct fwd_rule *new)
>   		warn("Too many rules (maximum %d)", ARRAY_SIZE(fwd->rules));
>   		return -ENOSPC;
>   	}
> +
>   	if ((fwd->sock_count + num) > ARRAY_SIZE(fwd->socks)) {
>   		warn("Rules require too many listening sockets (maximum %d)",
>   		     ARRAY_SIZE(fwd->socks));
>   		return -ENOSPC;
>   	}
> +	/* Redundant (see check just above), to make static checkers happy */
> +	if (fwd->sock_count > ARRAY_SIZE(fwd->socks))
> +		return -ENOSPC;
>   
>   	fwd->rulesocks[fwd->count] = &fwd->socks[fwd->sock_count];
> +
> +	/* Redundant, but not for static checkers, that might be missing that
> +	 * due to the check on 'num' above against ARRAY_SIZE(fwd->socks), we
> +	 * have a proper upper bound for new->last in the loop below.
> +	 */
> +	if (new->last > ARRAY_SIZE(fwd->socks) + new->first)
> +		return -ENOSPC;
>   	for (port = new->first; port <= new->last; port++)
>   		fwd->rulesocks[fwd->count][port - new->first] = -1;
>