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authorJack Pham <jackp@codeaurora.org>2014-02-18 22:16:19 -0800
committerBadhri Jagan Sridharan <badhri@google.com>2015-01-23 22:19:19 +0000
commitea262b409baefe776613660d6b7fdf029f5c96be (patch)
treef02ed4219a14dc5e07a4ff1fc6d78d782aa4d793
parentb3df6b14db2cb6919081441789e86ca2efceccca (diff)
downloadlinux-linaro-stable-ea262b409baefe776613660d6b7fdf029f5c96be.tar.gz
usb: gadget: android: Save/restore ep0 completion function
The android_setup() function currently gives the f_accessory setup function first opportunity to handle control requests in order to support Android Open Accessory (AOA) hosts. That function makes use of cdev->req and overrides its completion function, but not in all cases. Thus, if a later request uses the same request pointer but doesn't (re)set req->complete it could result in the wrong completion function being called and causing invalid memory access. One way to fix this would be to explicitly set req->complete in all cases but that might require auditing all function drivers that have ep0 handling. Instead, note that the composite device had already initially set cdev->req->complete and simply cache and restore that pointer at the start of android_setup(). Change-Id: I33bcd17bd20687a349d537d1013b52a2afef6996 Signed-off-by: Jack Pham <jackp@codeaurora.org>
-rw-r--r--drivers/usb/gadget/android.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/usb/gadget/android.c b/drivers/usb/gadget/android.c
index 04cbeb134814..83b1240d9b19 100644
--- a/drivers/usb/gadget/android.c
+++ b/drivers/usb/gadget/android.c
@@ -90,6 +90,9 @@ struct android_dev {
struct usb_composite_dev *cdev;
struct device *dev;
+ void (*setup_complete)(struct usb_ep *ep,
+ struct usb_request *req);
+
bool enabled;
int disable_depth;
struct mutex mutex;
@@ -1312,6 +1315,9 @@ static int android_bind(struct usb_composite_dev *cdev)
struct usb_gadget *gadget = cdev->gadget;
int id, ret;
+ /* Save the default handler */
+ dev->setup_complete = cdev->req->complete;
+
/*
* Start disconnected. Userspace will connect the gadget once
* it is done configuring the functions.
@@ -1378,6 +1384,7 @@ android_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *c)
req->zero = 0;
req->length = 0;
+ req->complete = dev->setup_complete;
gadget->ep0->driver_data = cdev;
list_for_each_entry(f, &dev->enabled_functions, enabled_list) {