From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhuang Jin Can Subject: [PATCH] usb: dwc3: gadget: Fix desc NULL pointer in dwc3_gadget_ep_queue() Date: Wed, 3 Sep 2014 14:26:34 +0800 Message-ID: <20140903062634.GA27870@intel.com> Reply-To: jin.can.zhuang@intel.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: balbi@ti.com Cc: david.a.cohen@intel.com, jiebing.li@intel.com, hang.yuan@intel.com, hao.wu@intel.com, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-omap@vger.kernel.org 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 Signed-off-by: Jiebing Li --- 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