[PATCH] usbredirhost: prevent overflow in usbredirhost_set_iso_threshold

[Anastasia Belova]

Cc'ing Victor Toso

01/07/24 14:11, Anastasia Belova:
> pkts_per_transfer < MAX_PACKETS_PER_TRANSFER = 32.
> transfer_count < MAX_TRANSFER_COUNT = 16.
> max_packetsize = maxp * mult. mult <= 3.
> maxp <= 0x7ff. If all variables have their max value,
> the result will be bigger that uint16_t.
> Add an explicit cast.
>
> Signed-off-by: Anastasia Belova <abelova at astralinux.ru>
> ---
>   usbredirhost/usbredirhost.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/usbredirhost/usbredirhost.c b/usbredirhost/usbredirhost.c
> index 03c56e9..ca19473 100644
> --- a/usbredirhost/usbredirhost.c
> +++ b/usbredirhost/usbredirhost.c
> @@ -1193,7 +1193,7 @@ static void usbredirhost_stop_stream(struct usbredirhost *host,
>   static void usbredirhost_set_iso_threshold(struct usbredirhost *host,
>       uint8_t pkts_per_transfer, uint8_t transfer_count, uint16_t max_packetsize)
>   {
> -    uint64_t reference = pkts_per_transfer * transfer_count * max_packetsize;
> +    uint64_t reference = (uint64_t)pkts_per_transfer * transfer_count * max_packetsize;
>       host->iso_threshold.lower = reference / 2;
>       host->iso_threshold.higher = reference * 3;
>       DEBUG("higher threshold is %" PRIu64 " bytes | lower threshold is %" PRIu64 " bytes",