Re: [PATCH] tests/qtest/netdev-socket: Avoid variable-length array in inet_get_free_port_multiple()

[Thomas Huth <thuth@redhat.com>]

On 24/08/2023 18.45, Peter Maydell wrote:
> We use a variable-length array in inet_get_free_port_multiple().
> This is only test code called at the start of a test, so switch to a
> heap allocation instead.
> 
> The codebase has very few VLAs, and if we can get rid of them all we
> can make the compiler error on new additions.  This is a defensive
> measure against security bugs where an on-stack dynamic allocation
> isn't correctly size-checked (e.g.  CVE-2021-3527).
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   tests/qtest/netdev-socket.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/qtest/netdev-socket.c b/tests/qtest/netdev-socket.c
> index 097abc0230b..8eed54801f2 100644
> --- a/tests/qtest/netdev-socket.c
> +++ b/tests/qtest/netdev-socket.c
> @@ -82,7 +82,7 @@ static int inet_get_free_port_socket_ipv6(int sock)
>   
>   static int inet_get_free_port_multiple(int nb, int *port, bool ipv6)
>   {
> -    int sock[nb];
> +    g_autofree int *sock = g_new(int, nb);
>       int i;
>   
>       for (i = 0; i < nb; i++) {

Reviewed-by: Thomas Huth <thuth@redhat.com>