| Message ID | 20230331090600.454674-1-pawell@cadence.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 1edf48991a783d00a3a18dc0d27c88139e4030a2 |
| Headers | show |
| Series | usb: cdnsp: Fixes error: uninitialized symbol 'len' | expand |
On Fri, Mar 31, 2023 at 05:06:00AM -0400, Pawel Laszczak wrote: > The patch 5bc38d33a5a1: "usb: cdnsp: Fixes issue with redundant > Status Stage" leads to the following Smatch static checker warning: > > drivers/usb/cdns3/cdnsp-ep0.c:470 cdnsp_setup_analyze() > error: uninitialized symbol 'len'. Are you sure this is correct? > > cc: <stable@vger.kernel.org> > Fixes: 5bc38d33a5a1 ("usb: cdnsp: Fixes issue with redundant Status Stage") > Signed-off-by: Pawel Laszczak <pawell@cadence.com> > --- > drivers/usb/cdns3/cdnsp-ep0.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/drivers/usb/cdns3/cdnsp-ep0.c b/drivers/usb/cdns3/cdnsp-ep0.c > index d63d5d92f255..f317d3c84781 100644 > --- a/drivers/usb/cdns3/cdnsp-ep0.c > +++ b/drivers/usb/cdns3/cdnsp-ep0.c > @@ -414,7 +414,7 @@ static int cdnsp_ep0_std_request(struct cdnsp_device *pdev, > void cdnsp_setup_analyze(struct cdnsp_device *pdev) > { > struct usb_ctrlrequest *ctrl = &pdev->setup; > - int ret = 0; > + int ret = -EINVAL; > u16 len; > > trace_cdnsp_ctrl_req(ctrl); > @@ -424,7 +424,6 @@ void cdnsp_setup_analyze(struct cdnsp_device *pdev) > > if (pdev->gadget.state == USB_STATE_NOTATTACHED) { > dev_err(pdev->dev, "ERR: Setup detected in unattached state\n"); > - ret = -EINVAL; That's a nice change, but I don't see the original error here that you are saying this change fixes. What am I missing? thanks, greg k-h
On 05.04.23 19:23, Greg KH wrote: > On Fri, Mar 31, 2023 at 05:06:00AM -0400, Pawel Laszczak wrote: >> { >> struct usb_ctrlrequest *ctrl = &pdev->setup; >> - int ret = 0; >> + int ret = -EINVAL; >> u16 len; >> >> trace_cdnsp_ctrl_req(ctrl); >> @@ -424,7 +424,6 @@ void cdnsp_setup_analyze(struct cdnsp_device *pdev) >> >> if (pdev->gadget.state == USB_STATE_NOTATTACHED) { >> dev_err(pdev->dev, "ERR: Setup detected in unattached state\n"); >> - ret = -EINVAL; > > That's a nice change, but I don't see the original error here that you > are saying this change fixes. > > What am I missing? The function has this check at its beginning: if (!pdev->gadget_driver) goto out; ret is initialized to 0 and len is uninitialized. The jump goes to: out: if (ret < 0) cdnsp_ep0_stall(pdev); else if (!len && pdev->ep0_stage != CDNSP_STATUS_STAGE) cdnsp_status_stage(pdev); The compiler (and an analysis tool) can determine that len will be evaluated in an uninitialized state. Setting ret to something negative prevents that. I must say this is convoluted, even though it is correct. HTH Oliver
On Wed, Apr 05, 2023 at 07:41:53PM +0200, Oliver Neukum wrote: > On 05.04.23 19:23, Greg KH wrote: > > On Fri, Mar 31, 2023 at 05:06:00AM -0400, Pawel Laszczak wrote: > > > > { > > > struct usb_ctrlrequest *ctrl = &pdev->setup; > > > - int ret = 0; > > > + int ret = -EINVAL; > > > u16 len; > > > trace_cdnsp_ctrl_req(ctrl); > > > @@ -424,7 +424,6 @@ void cdnsp_setup_analyze(struct cdnsp_device *pdev) > > > if (pdev->gadget.state == USB_STATE_NOTATTACHED) { > > > dev_err(pdev->dev, "ERR: Setup detected in unattached state\n"); > > > - ret = -EINVAL; > > > > That's a nice change, but I don't see the original error here that you > > are saying this change fixes. > > > > What am I missing? > > The function has this check at its beginning: > > if (!pdev->gadget_driver) > goto out; Argh, I missed this at the top of the function. I was looking further down, sorry for the noise. I'll go queue this up now, thanks. greg k-h
>On Fri, Mar 31, 2023 at 05:06:00AM -0400, Pawel Laszczak wrote: >> The patch 5bc38d33a5a1: "usb: cdnsp: Fixes issue with redundant Status >> Stage" leads to the following Smatch static checker warning: >> >> drivers/usb/cdns3/cdnsp-ep0.c:470 cdnsp_setup_analyze() >> error: uninitialized symbol 'len'. > >Are you sure this is correct? Yes, I'm sure. > >> >> cc: <stable@vger.kernel.org> >> Fixes: 5bc38d33a5a1 ("usb: cdnsp: Fixes issue with redundant Status >> Stage") >> Signed-off-by: Pawel Laszczak <pawell@cadence.com> >> --- >> drivers/usb/cdns3/cdnsp-ep0.c | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/drivers/usb/cdns3/cdnsp-ep0.c >> b/drivers/usb/cdns3/cdnsp-ep0.c index d63d5d92f255..f317d3c84781 >> 100644 >> --- a/drivers/usb/cdns3/cdnsp-ep0.c >> +++ b/drivers/usb/cdns3/cdnsp-ep0.c >> @@ -414,7 +414,7 @@ static int cdnsp_ep0_std_request(struct >> cdnsp_device *pdev, void cdnsp_setup_analyze(struct cdnsp_device >> *pdev) { >> struct usb_ctrlrequest *ctrl = &pdev->setup; >> - int ret = 0; >> + int ret = -EINVAL; >> u16 len; >> >> trace_cdnsp_ctrl_req(ctrl); >> @@ -424,7 +424,6 @@ void cdnsp_setup_analyze(struct cdnsp_device >> *pdev) >> >> if (pdev->gadget.state == USB_STATE_NOTATTACHED) { >> dev_err(pdev->dev, "ERR: Setup detected in unattached >state\n"); >> - ret = -EINVAL; > >That's a nice change, but I don't see the original error here that you are saying >this change fixes. > >What am I missing? The fixed patch is: Commit: 5bc38d33a5a1209fd4de65101d1ae8255ea12c6e And here you have the link to linux-next tree to this patch: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next-history.git/commit/?id=5bc38d33a5a1209fd4de65101d1ae8255ea12c6e I send this fix as v2 for patch "usb: cdnsp: Fixes issue with redundant Status Stage" but it was to late and you recommended me to send this as separate patch. Thanks and Regards, Pawel
diff --git a/drivers/usb/cdns3/cdnsp-ep0.c b/drivers/usb/cdns3/cdnsp-ep0.c index d63d5d92f255..f317d3c84781 100644 --- a/drivers/usb/cdns3/cdnsp-ep0.c +++ b/drivers/usb/cdns3/cdnsp-ep0.c @@ -414,7 +414,7 @@ static int cdnsp_ep0_std_request(struct cdnsp_device *pdev, void cdnsp_setup_analyze(struct cdnsp_device *pdev) { struct usb_ctrlrequest *ctrl = &pdev->setup; - int ret = 0; + int ret = -EINVAL; u16 len; trace_cdnsp_ctrl_req(ctrl); @@ -424,7 +424,6 @@ void cdnsp_setup_analyze(struct cdnsp_device *pdev) if (pdev->gadget.state == USB_STATE_NOTATTACHED) { dev_err(pdev->dev, "ERR: Setup detected in unattached state\n"); - ret = -EINVAL; goto out; }
The patch 5bc38d33a5a1: "usb: cdnsp: Fixes issue with redundant Status Stage" leads to the following Smatch static checker warning: drivers/usb/cdns3/cdnsp-ep0.c:470 cdnsp_setup_analyze() error: uninitialized symbol 'len'. cc: <stable@vger.kernel.org> Fixes: 5bc38d33a5a1 ("usb: cdnsp: Fixes issue with redundant Status Stage") Signed-off-by: Pawel Laszczak <pawell@cadence.com> --- drivers/usb/cdns3/cdnsp-ep0.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)