Re: [PATCH 2/2][next] net: usb: asix: ax88772: net: Fix less than zero comparison of a u16

From: Oleksij Rempel
Date: Tue Jun 08 2021 - 14:11:45 EST


On Tue, Jun 08, 2021 at 04:22:49PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>
> The comparison of the u16 priv->phy_addr < 0 is always false because
> phy_addr is unsigned. Fix this by assigning the return from the call
> to function asix_read_phy_addr to int ret and using this for the
> less than zero error check comparison.
>
> Addresses-Coverity: ("Unsigned compared against 0")
> Fixes: 7e88b11a862a ("net: usb: asix: refactor asix_read_phy_addr() and handle errors on return")

Here is wrong Fixes tag. This assignment was bogus before this patch.

> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> ---
> drivers/net/usb/ax88172a.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/usb/ax88172a.c b/drivers/net/usb/ax88172a.c
> index 2e2081346740..e24773bb9398 100644
> --- a/drivers/net/usb/ax88172a.c
> +++ b/drivers/net/usb/ax88172a.c
> @@ -205,7 +205,8 @@ static int ax88172a_bind(struct usbnet *dev, struct usb_interface *intf)
> goto free;
> }
>
> - priv->phy_addr = asix_read_phy_addr(dev, priv->use_embdphy);
> + ret = asix_read_phy_addr(dev, priv->use_embdphy);
> + priv->phy_addr = ret;

Ah.. it is same bug in different color :)
You probably wonted to do:
if (ret < 0)
goto free;

priv->phy_addr = ret;

> if (priv->phy_addr < 0) {
> ret = priv->phy_addr;
> goto free;
> --
> 2.31.1
>
>

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