From: changbin.du@intel.com
To: balbi@ti.com
Cc: gregkh@linuxfoundation.org, John.Youn@synopsys.com,
linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, "Du,
Changbin" <changbin.du@intel.com>
Subject: [PATCH v2] usb: gadget: forbid queuing request to a disabled ep
Date: Mon, 14 Dec 2015 11:48:46 +0800 [thread overview]
Message-ID: <1450064926-849-1-git-send-email-changbin.du@intel.com> (raw)
In-Reply-To: <87twnqi567.fsf@saruman.tx.rr.com>
From: "Du, Changbin" <changbin.du@intel.com>
Queue a request to disabled ep doesn't make sense, and induce caller
make mistakes.
Here is a example for the android mtp gadget function driver. A mem
corruption can happen on below senario.
1) On disconnect, mtp driver disable its EPs,
2) During send_file_work and receive_file_work, mtp queues a request
to ep. (The mtp driver need improve its synchronization logic!)
3) mtp_function_unbind is invoked and all mtp requests are freed.
4) when udc process the request queued on step 2, will cause kernel
NULL pointer dereference exception.
Signed-off-by: Du, Changbin <changbin.du@intel.com>
---
change from v1: add WARN_ON_ONCE message.
---
include/linux/usb/gadget.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 3d583a1..b566a4b 100644
--- a/include/linux/usb/gadget.h
+++ b/include/linux/usb/gadget.h
@@ -402,6 +402,9 @@ static inline void usb_ep_free_request(struct usb_ep *ep,
static inline int usb_ep_queue(struct usb_ep *ep,
struct usb_request *req, gfp_t gfp_flags)
{
+ if (WARN_ON_ONCE(!ep->enabled))
+ return -ESHUTDOWN;
+
return ep->ops->queue(ep, req, gfp_flags);
}
--
2.5.0
next prev parent reply other threads:[~2015-12-14 3:57 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-30 5:21 [PATCH 0/2] Two fix for dwc2 gadget driver changbin.du
2015-11-30 5:21 ` [PATCH 1/2] usb: dwc2: add ep enabled flag to avoid double enable/disable changbin.du
2015-12-10 17:26 ` Felipe Balbi
2015-12-14 3:23 ` Du, Changbin
2015-11-30 5:21 ` [PATCH 2/2] usb: dwc2: forbid queuing request to a disabled ep changbin.du
2015-12-10 17:27 ` Felipe Balbi
2015-12-03 1:20 ` [PATCH 0/2] Two fix for dwc2 gadget driver John Youn
2015-12-03 4:23 ` Du, Changbin
2015-12-04 7:21 ` [PATCH] usb: gadget: forbid queuing request to a disabled ep changbin.du
2015-12-10 17:28 ` Felipe Balbi
2015-12-14 3:48 ` changbin.du [this message]
2015-12-14 10:20 ` [PATCH v2] " Du, Changbin
2015-12-16 16:52 ` Felipe Balbi
2015-12-17 9:35 ` Du, Changbin
2015-12-17 10:00 ` [PATCH v3] " changbin.du
2015-12-17 15:26 ` Felipe Balbi
2015-12-18 7:34 ` Du, Changbin
2015-12-18 7:36 ` [PATCH v4] " changbin.du
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