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Subject[PATCH] usb: dwc3: gadget: Fix desc NULL pointer in dwc3_gadget_ep_queue()
dep->endpoint.desc is checked at the beginning of
dwc3_gadget_ep_queue(), but after that it may be set to NULL
by another thread and then accessed again in dwc3_gadget_ep_queue().
This will lead to kernel oops.

Expand spinlock protection area to aviod race condition.

Signed-off-by: Zhuang Jin Can <jin.can.zhuang@intel.com>
Signed-off-by: Jiebing Li <jiebing.li@intel.com>
---
drivers/usb/dwc3/gadget.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 349cacc..e8fb231 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1225,16 +1225,17 @@ static int dwc3_gadget_ep_queue(struct usb_ep *ep, struct usb_request *request,

int ret;

+ spin_lock_irqsave(&dwc->lock, flags);
if (!dep->endpoint.desc) {
dev_dbg(dwc->dev, "trying to queue request %p to disabled %s\n",
request, ep->name);
+ spin_unlock_irqrestore(&dwc->lock, flags);
return -ESHUTDOWN;
}

dev_vdbg(dwc->dev, "queing request %p to %s length %d\n",
request, ep->name, request->length);

- spin_lock_irqsave(&dwc->lock, flags);
ret = __dwc3_gadget_ep_queue(dep, req);
spin_unlock_irqrestore(&dwc->lock, flags);

--
1.7.9.5


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