[PATCH v3] nss: Use reallocarray to prevent integer overflow in getaddrinfo (bug 33977)

[Arjun Shankar]

> replacing realloc by reallocarray introduces a basic overflow check.
> (old + count) might still overflow, but since the NSS backend is trusted,
> we do not consider this to be a valid case.

Thanks! This looks good to me.

Reviewed-by: Arjun Shankar <arjun@redhat.com>

> ---
> v1: https://inbox.sourceware.org/libc-alpha/77a01db3-5619-48b8-9682-85f11cc472bc@crystaldown.de/
> v2: iterated on Arjuns and Andreas review comments
> v3: re-submission to support existing tooling
> ---
>  nss/getaddrinfo.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/nss/getaddrinfo.c b/nss/getaddrinfo.c
> index 4f6ac3358a..b6ac0b2dcc 100644
> --- a/nss/getaddrinfo.c
> +++ b/nss/getaddrinfo.c
> @@ -234,7 +234,7 @@ convert_hostent_to_gaih_addrtuple (const struct addrinfo *req, int family,
>        array = array->next;
>      }
>
> -  array = realloc (res->at, (old + count) * sizeof (*array));
> +  array = reallocarray (res->at, old + count, sizeof (*array));
>
>    if (array == NULL)
>      return false;
> --
> 2.47.3
>


-- 
Arjun Shankar
he/him/his