diff mbox series

usb: cdns3: Don't use priv_dev uninitialized in cdns3_gadget_ep_enable()

Message ID 20220803162422.2981308-1-nathan@kernel.org (mailing list archive)
State Accepted
Commit 78acd4ca433425e6dd4032cfc2156c60e34931f2
Headers show
Series usb: cdns3: Don't use priv_dev uninitialized in cdns3_gadget_ep_enable() | expand

Commit Message

Nathan Chancellor Aug. 3, 2022, 4:24 p.m. UTC
Clang warns:

  drivers/usb/cdns3/cdns3-gadget.c:2290:11: error: variable 'priv_dev' is uninitialized when used here [-Werror,-Wuninitialized]
                  dev_dbg(priv_dev->dev, "usbss: invalid parameters\n");
                          ^~~~~~~~
  include/linux/dev_printk.h:155:18: note: expanded from macro 'dev_dbg'
          dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
                          ^~~
  include/linux/dynamic_debug.h:167:7: note: expanded from macro 'dynamic_dev_dbg'
                          dev, fmt, ##__VA_ARGS__)
                          ^~~
  include/linux/dynamic_debug.h:152:56: note: expanded from macro '_dynamic_func_call'
          __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
                                                              ^~~~~~~~~~~
  include/linux/dynamic_debug.h:134:15: note: expanded from macro '__dynamic_func_call'
                  func(&id, ##__VA_ARGS__);               \
                              ^~~~~~~~~~~
  drivers/usb/cdns3/cdns3-gadget.c:2278:31: note: initialize the variable 'priv_dev' to silence this warning
          struct cdns3_device *priv_dev;
                                      ^
                                      = NULL
  1 error generated.

The priv_dev assignment was moved below the if statement to avoid
potentially dereferencing ep before it was checked but priv_dev is used
in the dev_dbg() call.

To fix this, move the priv_dev and comp_desc assignments back to their
original spot and hoist the ep check above those assignments with a call
to pr_debug() instead of dev_dbg().

Fixes: c3ffc9c4ca44 ("usb: cdns3: change place of 'priv_ep' assignment in cdns3_gadget_ep_dequeue(), cdns3_gadget_ep_enable()")
Link: https://github.com/ClangBuiltLinux/linux/issues/1680
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/usb/cdns3/cdns3-gadget.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)


base-commit: 8288c99fc263bcafc5df5fa8c278b2eb8106364e

Comments

Peter Chen Aug. 18, 2022, 10:51 p.m. UTC | #1
On 22-08-03 09:24:22, Nathan Chancellor wrote:
> Clang warns:
> 
>   drivers/usb/cdns3/cdns3-gadget.c:2290:11: error: variable 'priv_dev' is uninitialized when used here [-Werror,-Wuninitialized]
>                   dev_dbg(priv_dev->dev, "usbss: invalid parameters\n");
>                           ^~~~~~~~
>   include/linux/dev_printk.h:155:18: note: expanded from macro 'dev_dbg'
>           dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
>                           ^~~
>   include/linux/dynamic_debug.h:167:7: note: expanded from macro 'dynamic_dev_dbg'
>                           dev, fmt, ##__VA_ARGS__)
>                           ^~~
>   include/linux/dynamic_debug.h:152:56: note: expanded from macro '_dynamic_func_call'
>           __dynamic_func_call(__UNIQUE_ID(ddebug), fmt, func, ##__VA_ARGS__)
>                                                               ^~~~~~~~~~~
>   include/linux/dynamic_debug.h:134:15: note: expanded from macro '__dynamic_func_call'
>                   func(&id, ##__VA_ARGS__);               \
>                               ^~~~~~~~~~~
>   drivers/usb/cdns3/cdns3-gadget.c:2278:31: note: initialize the variable 'priv_dev' to silence this warning
>           struct cdns3_device *priv_dev;
>                                       ^
>                                       = NULL
>   1 error generated.
> 
> The priv_dev assignment was moved below the if statement to avoid
> potentially dereferencing ep before it was checked but priv_dev is used
> in the dev_dbg() call.
> 
> To fix this, move the priv_dev and comp_desc assignments back to their
> original spot and hoist the ep check above those assignments with a call
> to pr_debug() instead of dev_dbg().
> 
> Fixes: c3ffc9c4ca44 ("usb: cdns3: change place of 'priv_ep' assignment in cdns3_gadget_ep_dequeue(), cdns3_gadget_ep_enable()")
> Link: https://github.com/ClangBuiltLinux/linux/issues/1680
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Acked-by: Peter Chen <peter.chen@kernel.org>

> ---
>  drivers/usb/cdns3/cdns3-gadget.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
> index 9ac7d0a8c5da..d21b69997e75 100644
> --- a/drivers/usb/cdns3/cdns3-gadget.c
> +++ b/drivers/usb/cdns3/cdns3-gadget.c
> @@ -2284,16 +2284,20 @@ static int cdns3_gadget_ep_enable(struct usb_ep *ep,
>  	int ret = 0;
>  	int val;
>  
> +	if (!ep) {
> +		pr_debug("usbss: ep not configured?\n");
> +		return -EINVAL;
> +	}
> +
>  	priv_ep = ep_to_cdns3_ep(ep);
> +	priv_dev = priv_ep->cdns3_dev;
> +	comp_desc = priv_ep->endpoint.comp_desc;
>  
> -	if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
> +	if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
>  		dev_dbg(priv_dev->dev, "usbss: invalid parameters\n");
>  		return -EINVAL;
>  	}
>  
> -	comp_desc = priv_ep->endpoint.comp_desc;
> -	priv_dev = priv_ep->cdns3_dev;
> -
>  	if (!desc->wMaxPacketSize) {
>  		dev_err(priv_dev->dev, "usbss: missing wMaxPacketSize\n");
>  		return -EINVAL;
> 
> base-commit: 8288c99fc263bcafc5df5fa8c278b2eb8106364e
> -- 
> 2.37.1
>
diff mbox series

Patch

diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index 9ac7d0a8c5da..d21b69997e75 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -2284,16 +2284,20 @@  static int cdns3_gadget_ep_enable(struct usb_ep *ep,
 	int ret = 0;
 	int val;
 
+	if (!ep) {
+		pr_debug("usbss: ep not configured?\n");
+		return -EINVAL;
+	}
+
 	priv_ep = ep_to_cdns3_ep(ep);
+	priv_dev = priv_ep->cdns3_dev;
+	comp_desc = priv_ep->endpoint.comp_desc;
 
-	if (!ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
+	if (!desc || desc->bDescriptorType != USB_DT_ENDPOINT) {
 		dev_dbg(priv_dev->dev, "usbss: invalid parameters\n");
 		return -EINVAL;
 	}
 
-	comp_desc = priv_ep->endpoint.comp_desc;
-	priv_dev = priv_ep->cdns3_dev;
-
 	if (!desc->wMaxPacketSize) {
 		dev_err(priv_dev->dev, "usbss: missing wMaxPacketSize\n");
 		return -EINVAL;