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authorDu, Changbin <changbin.du@intel.com>2015-12-18 15:36:40 +0800
committerFelipe Balbi <balbi@ti.com>2015-12-22 12:04:05 -0600
commit8a0859b65b06ea07461271ce4f1fe25b48d1ec55 (patch)
treebc345d9e4aadb539983ea114dacbf11cdfd9de35 /include
parent6d76c92c2fcbee4fd1f6d7b375d71057c7a615b1 (diff)
usb: gadget: forbid queuing request to a disabled ep
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> Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'include')
-rw-r--r--include/linux/usb/gadget.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
index 92467eea76de..d82d0068872b 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 && ep->address))
+ return -ESHUTDOWN;
+
return ep->ops->queue(ep, req, gfp_flags);
}