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

On 08/06/2021 19:11, Oleksij Rempel wrote:

On Tue, Jun 08, 2021 at 04:22:49PM +0100, Colin King wrote:

quoted

From: Colin Ian King <redacted>

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.

I'm not sure that's correct, that commit has the following change in it:

diff --git a/drivers/net/usb/ax88172a.c b/drivers/net/usb/ax88172a.c
index b404c9462dce..c8ca5187eece 100644
--- a/drivers/net/usb/ax88172a.c
+++ b/drivers/net/usb/ax88172a.c

@@ -220,6 +220,11 @@ static int ax88172a_bind(struct usbnet *dev, struct

usb_interface *intf)
        }

        priv->phy_addr = asix_read_phy_addr(dev, priv->use_embdphy);
+       if (priv->phy_addr < 0) {
+               ret = priv->phy_addr;
+               goto free;
+       }
+

quoted

Signed-off-by: Colin Ian King <redacted>
---
 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;

Doh, brain failure of mine. I'll send a V2 later today.

quoted

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