linux-kernel - [PATCH 1/1] USBHID: correct start/stop cycle

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Date:	Sat,  1 Nov 2008 23:41:46 +0100
From:	Jiri Slaby <jirislaby@...il.com>
To:	jkosina@...e.cz
Cc:	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
	Jiri Slaby <jirislaby@...il.com>
Subject: [PATCH 1/1] USBHID: correct start/stop cycle

`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'.

Signed-off-by: Jiri Slaby <jirislaby@...il.com>
---
 drivers/hid/usbhid/hid-core.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index 18e5ddd..f0339ae 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -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);
-- 
1.6.0.3

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