Re: [PATCH] remoteproc: harden rproc_handle_vdev() against integer overflow

["Gustavo A. R. Silva" <gustavoars@kernel.org>]

On Thu, Sep 15, 2022 at 05:11:44PM +0300, Dan Carpenter wrote:
> The struct_size() macro protects against integer overflows but adding
> "+ rsc->config_len" introduces the risk of integer overflows again.
> Use size_add() to be safe.
> 
> Fixes: c87846571587 ("remoteproc: use struct_size() helper")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks!
--
Gustavo

> ---
>  drivers/remoteproc/remoteproc_core.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c
> index e5279ed9a8d7..4fc5ce2187ac 100644
> --- a/drivers/remoteproc/remoteproc_core.c
> +++ b/drivers/remoteproc/remoteproc_core.c
> @@ -520,12 +520,13 @@ static int rproc_handle_vdev(struct rproc *rproc, void *ptr,
>  	struct fw_rsc_vdev *rsc = ptr;
>  	struct device *dev = &rproc->dev;
>  	struct rproc_vdev *rvdev;
> +	size_t rsc_size;
>  	int i, ret;
>  	char name[16];
>  
>  	/* make sure resource isn't truncated */
> -	if (struct_size(rsc, vring, rsc->num_of_vrings) + rsc->config_len >
> -			avail) {
> +	rsc_size = struct_size(rsc, vring, rsc->num_of_vrings);
> +	if (size_add(rsc_size, rsc->config_len) > avail) {
>  		dev_err(dev, "vdev rsc is truncated\n");
>  		return -EINVAL;
>  	}
> -- 
> 2.35.1
>