From 78acd4ca433425e6dd4032cfc2156c60e34931f2 Mon Sep 17 00:00:00 2001

From: Nathan Chancellor <nathan@kernel.org>

Date: Wed, 3 Aug 2022 09:24:22 -0700

Subject: [PATCH] usb: cdns3: Don't use priv_dev uninitialized in cdns3_gadget_ep_enable()

Git-commit: 78acd4ca433425e6dd4032cfc2156c60e34931f2

Patch-mainline: v6.0-rc1

References: git-fixes

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>

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 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;

-- 

2.35.3