On Sat, 2012-08-18 at 18:58 +0300, Dan Carpenter wrote:
> "carrier" comes from a get_user() in ir_lirc_ioctl().  We need to test
> that it's not zero before using it as a divisor.

Other RC drivers seem to have the same problem, only more deeply buried.
I think it's better to put this check in ir_lirc_ioctl() instead,
consistent with LIRC_SET_REC_CARRIER.

Ben.

> Signed-off-by: Dan Carpenter <dan.carpen...@oracle.com>
> 
> diff --git a/drivers/media/rc/ene_ir.c b/drivers/media/rc/ene_ir.c
> index 647dd95..d05ac15 100644
> --- a/drivers/media/rc/ene_ir.c
> +++ b/drivers/media/rc/ene_ir.c
> @@ -881,10 +881,13 @@ static int ene_set_tx_mask(struct rc_dev *rdev, u32 
> tx_mask)
>  static int ene_set_tx_carrier(struct rc_dev *rdev, u32 carrier)
>  {
>       struct ene_device *dev = rdev->priv;
> -     u32 period = 2000000 / carrier;
> +     u32 period;
>  
>       dbg("TX: attempt to set tx carrier to %d kHz", carrier);
> +     if (carrier == 0)
> +             return -EINVAL;
>  
> +     period = 2000000 / carrier;
>       if (period && (period > ENE_CIRMOD_PRD_MAX ||
>                       period < ENE_CIRMOD_PRD_MIN)) {
>  
> diff --git a/drivers/media/rc/nuvoton-cir.c b/drivers/media/rc/nuvoton-cir.c
> index 699eef3..2ea913a 100644
> --- a/drivers/media/rc/nuvoton-cir.c
> +++ b/drivers/media/rc/nuvoton-cir.c
> @@ -517,6 +517,9 @@ static int nvt_set_tx_carrier(struct rc_dev *dev, u32 
> carrier)
>       struct nvt_dev *nvt = dev->priv;
>       u16 val;
>  
> +     if (carrier == 0)
> +             return -EINVAL;
> +
>       nvt_cir_reg_write(nvt, 1, CIR_CP);
>       val = 3000000 / (carrier) - 1;
>       nvt_cir_reg_write(nvt, val & 0xff, CIR_CC);
> 

-- 
Ben Hutchings
I say we take off; nuke the site from orbit.  It's the only way to be sure.

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