HID: fix start/stop cycle in usbhid driver
Jiri Slaby [Sat, 1 Nov 2008 22:41:46 +0000 (23:41 +0100)]
`stop' left out usbhid->urb* pointers and so the next `start' thought
it needs to allocate nothing and used the memory pointers previously
pointed to. This led to memory corruption and device malfunction.

Also don't forget to clear disconnect flag on start which was left set
by the previous `stop'.

This fixes

echo DEVICE > /sys/bus/hid/drivers/DRIVER/unbind
echo DEVICE > /sys/bus/hid/drivers/DRIVER/bind

failures.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/usbhid/hid-core.c

index 18e5ddd..f0339ae 100644 (file)
@@ -781,6 +781,8 @@ static int usbhid_start(struct hid_device *hid)
        unsigned int n, insize = 0;
        int ret;
 
+       clear_bit(HID_DISCONNECTED, &usbhid->iofl);
+
        usbhid->bufsize = HID_MIN_BUFFER_SIZE;
        hid_find_max_report(hid, HID_INPUT_REPORT, &usbhid->bufsize);
        hid_find_max_report(hid, HID_OUTPUT_REPORT, &usbhid->bufsize);
@@ -888,6 +890,9 @@ fail:
        usb_free_urb(usbhid->urbin);
        usb_free_urb(usbhid->urbout);
        usb_free_urb(usbhid->urbctrl);
+       usbhid->urbin = NULL;
+       usbhid->urbout = NULL;
+       usbhid->urbctrl = NULL;
        hid_free_buffers(dev, hid);
        mutex_unlock(&usbhid->setup);
        return ret;
@@ -924,6 +929,9 @@ static void usbhid_stop(struct hid_device *hid)
        usb_free_urb(usbhid->urbin);
        usb_free_urb(usbhid->urbctrl);
        usb_free_urb(usbhid->urbout);
+       usbhid->urbin = NULL; /* don't mess up next start */
+       usbhid->urbctrl = NULL;
+       usbhid->urbout = NULL;
 
        hid_free_buffers(hid_to_usb_dev(hid), hid);
        mutex_unlock(&usbhid->setup);