Re: [PATCH 2/4] hw/net/rocker: Avoid variable length array

[Francisco Iglesias]

On [2023 Aug 24] Thu 16:32:22, Peter Maydell wrote:
> Replace an on-stack variable length array in of_dpa_ig() with
> a g_autofree heap allocation.
> 
> 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>

Reviewed-by: Francisco Iglesias <frasse.iglesias@gmail.com>

> ---
>  hw/net/rocker/rocker_of_dpa.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/net/rocker/rocker_of_dpa.c b/hw/net/rocker/rocker_of_dpa.c
> index dfe47544694..5e16056be66 100644
> --- a/hw/net/rocker/rocker_of_dpa.c
> +++ b/hw/net/rocker/rocker_of_dpa.c
> @@ -1043,7 +1043,7 @@ static void of_dpa_flow_ig_tbl(OfDpaFlowContext *fc, 
> uint32_t tbl_id)
>  static ssize_t of_dpa_ig(World *world, uint32_t pport,
>                           const struct iovec *iov, int iovcnt)
>  {
> -    struct iovec iov_copy[iovcnt + 2];
> +    g_autofree struct iovec *iov_copy = g_new(struct iovec, iovcnt + 2);
>      OfDpaFlowContext fc = {
>          .of_dpa = world_private(world),
>          .in_pport = pport,
> -- 
> 2.34.1
> 
>