Re: [PATCH 1/3] tools: hv: fcopy_daemon: Check buffer limits

From: One Thousand Gnomes
Date: Tue Oct 21 2014 - 08:14:27 EST


On Tue, 21 Oct 2014 13:49:00 +0200
Matej MuÅila <mmuzila@xxxxxxxxxx> wrote:

> From: Matej MuÅila <mmuzila@xxxxxxxxxx>
>
> Check if cpmsg->size is in limits of DATA_FRAGMENT
>
> Signed-off-by: Matej MuÅila <mmuzila@xxxxxxxxxx>
> Acked-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
> ---
> If corrupted data are read from /dev/vmbus/hv_fcopy, pwrite can
> read from memory outside of the buffer (defined at line 138).
> Added check.
> ---
> @@ -104,6 +104,10 @@ static int hv_copy_data(struct hv_do_fcopy *cpmsg)
> {
> ssize_t bytes_written;
>
> + // Check if the cpmsg->size is in limits of DATA_FRAGMENT
> + if (cpmsg->size > DATA_FRAGMENT * sizeof(__u8))
> + return HV_E_FAIL;
> +

- C style comments for coding style, also sizeof(__u8) is by definition 1
so it's perhaps surplus ?

Also your patch block is devoid of a few thins like the file name...
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