[PATCH 5.18 0825/1095] usb: cdns3: Dont use priv_dev uninitialized in cdns3_gadget_ep_enable()

Greg Kroah-Hartman
2022-08-15T22:38:06Z

From: Nathan Chancellor <nathan@kernel.org>

[ Upstream commit 78acd4ca433425e6dd4032cfc2156c60e34931f2 ]

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>
Signed-off-by: Sasha Levin <sashal@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 e0cf62e65075..ae049eb28b93 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -2280,16 +2280,20 @@ 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;
--
2.35.1