Re: [PATCH v2] mt76/mt7915: Fix unsigned compared against zero

[Greg KH]

On Sun, Jul 04, 2021 at 04:59:20PM +0200, John Wood wrote:
> The mt7915_dpd_freq_idx() function can return a negative value but this
> value is assigned to an unsigned variable named idx. Then, the code
> tests if this variable is less than zero. This can never happen with an
> unsigned type.
> 
> So, change the idx type to a signed one.
> 
> Addresses-Coverity-ID: 1484753 ("Unsigned compared against 0")
> Fixes: 495184ac91bb8 ("mt76: mt7915: add support for applying pre-calibration data")
> Signed-off-by: John Wood <john.wood@xxxxxxx>
> ---
> Changelog v1 -> v2
> - Add Cc to stable@xxxxxxxxxxxxxxx
> 
>  drivers/net/wireless/mediatek/mt76/mt7915/mcu.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
> index b3f14ff67c5a..764f25a828fa 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
> @@ -3440,8 +3440,9 @@ int mt7915_mcu_apply_tx_dpd(struct mt7915_phy *phy)
>  {
>  	struct mt7915_dev *dev = phy->dev;
>  	struct cfg80211_chan_def *chandef = &phy->mt76->chandef;
> -	u16 total = 2, idx, center_freq = chandef->center_freq1;
> +	u16 total = 2, center_freq = chandef->center_freq1;
>  	u8 *cal = dev->cal, *eep = dev->mt76.eeprom.data;
> +	int idx;
> 
>  	if (!(eep[MT_EE_DO_PRE_CAL] & MT_EE_WIFI_CAL_DPD))
>  		return 0;
> --
> 2.25.1
> 
<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>