Re: [PATCH v6 2/5] parallels: Check if data_end greater than the file size

[Denis V. Lunev]

On 6/21/23 10:20, Alexander Ivanov wrote:
> Initially data_end is set to the data_off image header field and must not be
> greater than the file size.
>
> Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
> ---
>   block/parallels.c | 5 +++++
>   1 file changed, 5 insertions(+)
>
> diff --git a/block/parallels.c b/block/parallels.c
> index 1ec98c722b..4b7eafba1e 100644
> --- a/block/parallels.c
> +++ b/block/parallels.c
> @@ -868,6 +868,11 @@ static int parallels_open(BlockDriverState *bs, QDict 
> *options, int flags,
>              and actual data. We can't avoid read-modify-write... */
>           s->header_size = size;
>       }
> +    if (s->data_end > file_nb_sectors) {
> +        error_setg(errp, "Invalid image: incorrect data_off field");
> +        ret = -EINVAL;
> +        goto fail;
> +    }
>   
>       ret = bdrv_pread(bs->file, 0, s->header_size, s->header, 0);
>       if (ret < 0) {
for me this seems incorrect. In this case we would not be able to EVER
open such image, even for a check purpose.

This place should have a clause like

            if (!(flags & BDRV_O_CHECK)) {
                goto fail
            }

This error is not fatal from the check point of view.

Den