| Message ID | 20190925105911.GI3264@mwanda |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] net: axienet: fix a signedness bug in probe | expand |
Hi, Dan On Wed, Sep 25, 2019 at 01:59:11PM +0300, Dan Carpenter wrote: > The "lp->phy_mode" is an enum but in this context GCC treats it as an > unsigned int so the error handling is never triggered. > > lp->phy_mode = of_get_phy_mode(pdev->dev.of_node); > - if (lp->phy_mode < 0) { > + if ((int)lp->phy_mode < 0) { This (almost) exact code appears in a lot of different drivers too, so maybe it'd be nice to review them all and apply the same cast if needed? Best regards
From: "Alvaro G. M" <alvaro.gamez@hazent.com> Date: Wed, 25 Sep 2019 13:05:43 +0200 > Hi, Dan > > On Wed, Sep 25, 2019 at 01:59:11PM +0300, Dan Carpenter wrote: >> The "lp->phy_mode" is an enum but in this context GCC treats it as an >> unsigned int so the error handling is never triggered. >> >> lp->phy_mode = of_get_phy_mode(pdev->dev.of_node); >> - if (lp->phy_mode < 0) { >> + if ((int)lp->phy_mode < 0) { > > This (almost) exact code appears in a lot of different drivers too, > so maybe it'd be nice to review them all and apply the same cast if needed? Or make the thing an int if negative values are never valid 32-bit phy_mode values anyways.
> -----Original Message----- > From: Dan Carpenter <dan.carpenter@oracle.com> > Sent: Wednesday, September 25, 2019 4:29 PM > To: Radhey Shyam Pandey <radheys@xilinx.com>; Alvaro G. M > <alvaro.gamez@hazent.com> > Cc: David S. Miller <davem@davemloft.net>; Michal Simek > <michals@xilinx.com>; Russell King <linux@armlinux.org.uk>; > netdev@vger.kernel.org; kernel-janitors@vger.kernel.org > Subject: [PATCH net] net: axienet: fix a signedness bug in probe > > The "lp->phy_mode" is an enum but in this context GCC treats it as an > unsigned int so the error handling is never triggered. > > Fixes: ee06b1728b95 ("net: axienet: add support for standard phy-mode > binding") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com> > --- > drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c > b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c > index 4fc627fb4d11..676006f32f91 100644 > --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c > +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c > @@ -1762,7 +1762,7 @@ static int axienet_probe(struct platform_device > *pdev) > } > } else { > lp->phy_mode = of_get_phy_mode(pdev->dev.of_node); > - if (lp->phy_mode < 0) { > + if ((int)lp->phy_mode < 0) { > ret = -EINVAL; > goto free_netdev; > } > -- > 2.20.1
On Wed, Sep 25, 2019 at 01:35:07PM +0200, David Miller wrote: > From: "Alvaro G. M" <alvaro.gamez@hazent.com> > Date: Wed, 25 Sep 2019 13:05:43 +0200 > > > Hi, Dan > > > > On Wed, Sep 25, 2019 at 01:59:11PM +0300, Dan Carpenter wrote: > >> The "lp->phy_mode" is an enum but in this context GCC treats it as an > >> unsigned int so the error handling is never triggered. > >> > >> lp->phy_mode = of_get_phy_mode(pdev->dev.of_node); > >> - if (lp->phy_mode < 0) { > >> + if ((int)lp->phy_mode < 0) { > > > > This (almost) exact code appears in a lot of different drivers too, > > so maybe it'd be nice to review them all and apply the same cast if needed? > > Or make the thing an int if negative values are never valid 32-bit phy_mode > values anyways. Maybe we should change the API int of_get_phy_mode(struct device_node *np, phy_interface_t *phy_mode); Separate the error from the value we are getting. Andrew
On Wed, Sep 25, 2019 at 01:05:43PM +0200, Alvaro G. M wrote: > Hi, Dan > > On Wed, Sep 25, 2019 at 01:59:11PM +0300, Dan Carpenter wrote: > > The "lp->phy_mode" is an enum but in this context GCC treats it as an > > unsigned int so the error handling is never triggered. > > > > lp->phy_mode = of_get_phy_mode(pdev->dev.of_node); > > - if (lp->phy_mode < 0) { > > + if ((int)lp->phy_mode < 0) { > > This (almost) exact code appears in a lot of different drivers too, > so maybe it'd be nice to review them all and apply the same cast if needed? > This is a new warning in Smatch. I did send patches for the whole kernel. We won't get these bugs in the future because people run Smatch on the kernel and will find the bugs. All the bugs were from 2017 or later which suggests that someone cleared these out two years ago but soon the 0-day bot will warn about issues so they will get fixed quicker. I'm sort of out of it today... The get_phy_mode() function seem like they lend themselves to creating these bugs. The ->phy_mode variables tend to be declared in the driver so it would require quite a few patches to make them all int and I'm not sure that's more beautiful. Andrew Lunn's idea to update the API would probably be a good idea. I'm going back to bed for now and I'll think about this some more. regards, dan carpenter
> The get_phy_mode() function seem like they lend themselves to creating > these bugs. The ->phy_mode variables tend to be declared in the driver > so it would require quite a few patches to make them all int and I'm not > sure that's more beautiful. Andrew Lunn's idea to update the API would > probably be a good idea. Hi Dan I started on it. Once net-next has opened, and 0-day has compile tested my changes, i will post the code for review. Andrew
From: Dan Carpenter <dan.carpenter@oracle.com> Date: Wed, 25 Sep 2019 13:59:11 +0300 > The "lp->phy_mode" is an enum but in this context GCC treats it as an > unsigned int so the error handling is never triggered. > > Fixes: ee06b1728b95 ("net: axienet: add support for standard phy-mode binding") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Applied.
diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c index 4fc627fb4d11..676006f32f91 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -1762,7 +1762,7 @@ static int axienet_probe(struct platform_device *pdev) } } else { lp->phy_mode = of_get_phy_mode(pdev->dev.of_node); - if (lp->phy_mode < 0) { + if ((int)lp->phy_mode < 0) { ret = -EINVAL; goto free_netdev; }
The "lp->phy_mode" is an enum but in this context GCC treats it as an unsigned int so the error handling is never triggered. Fixes: ee06b1728b95 ("net: axienet: add support for standard phy-mode binding") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)