[ 023/150] rtlwifi: usb: allocate URB control message setup_packet and data buffer separately

Greg Kroah-Hartman
2013-02-27T01:16:41Z

From: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>

commit bc6b89237acb3dee6af6e64e51a18255fef89cc2 upstream.

rtlwifi allocates both setup_packet and data buffer of control message urb,
using shared kmalloc in _usbctrl_vendorreq_async_write. Structure used for
allocating is:
struct {
u8 data[254];
struct usb_ctrlrequest dr;
};

Because 'struct usb_ctrlrequest' is __packed, setup packet is unaligned and
DMA mapping of both 'data' and 'dr' confuses ARM/sunxi, leading to memory
corruptions and freezes.

Patch changes setup packet to be allocated separately.

[v2]:
- Use WARN_ON_ONCE instead of WARN_ON

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/wireless/rtlwifi/usb.c | 44 +++++++++++++++++++++++--------------
1 file changed, 28 insertions(+), 16 deletions(-)

--- a/drivers/net/wireless/rtlwifi/usb.c
+++ b/drivers/net/wireless/rtlwifi/usb.c
@@ -42,8 +42,12 @@

static void usbctrl_async_callback(struct urb *urb)
{
- if (urb)
- kfree(urb->context);
+ if (urb) {
+ /* free dr */
+ kfree(urb->setup_packet);
+ /* free databuf */
+ kfree(urb->transfer_buffer);
+ }
}

static int _usbctrl_vendorreq_async_write(struct usb_device *udev, u8 request,
@@ -55,39 +59,47 @@ static int _usbctrl_vendorreq_async_writ
u8 reqtype;
struct usb_ctrlrequest *dr;
struct urb *urb;
- struct rtl819x_async_write_data {
- u8 data[REALTEK_USB_VENQT_MAX_BUF_SIZE];
- struct usb_ctrlrequest dr;
- } *buf;
+ const u16 databuf_maxlen = REALTEK_USB_VENQT_MAX_BUF_SIZE;
+ u8 *databuf;
+
+ if (WARN_ON_ONCE(len > databuf_maxlen))
+ len = databuf_maxlen;

pipe = usb_sndctrlpipe(udev, 0); /* write_out */
reqtype = REALTEK_USB_VENQT_WRITE;

- buf = kmalloc(sizeof(*buf), GFP_ATOMIC);
- if (!buf)
+ dr = kmalloc(sizeof(*dr), GFP_ATOMIC);
+ if (!dr)
return -ENOMEM;

+ databuf = kmalloc(databuf_maxlen, GFP_ATOMIC);
+ if (!databuf) {
+ kfree(dr);
+ return -ENOMEM;
+ }
+
urb = usb_alloc_urb(0, GFP_ATOMIC);
if (!urb) {
- kfree(buf);
+ kfree(databuf);
+ kfree(dr);
return -ENOMEM;
}

- dr = &buf->dr;
-
dr->bRequestType = reqtype;
dr->bRequest = request;
dr->wValue = cpu_to_le16(value);
dr->wIndex = cpu_to_le16(index);
dr->wLength = cpu_to_le16(len);
/* data are already in little-endian order */
- memcpy(buf, pdata, len);
+ memcpy(databuf, pdata, len);
usb_fill_control_urb(urb, udev, pipe,
- (unsigned char *)dr, buf, len,
- usbctrl_async_callback, buf);
+ (unsigned char *)dr, databuf, len,
+ usbctrl_async_callback, NULL);
rc = usb_submit_urb(urb, GFP_ATOMIC);
- if (rc < 0)
- kfree(buf);
+ if (rc < 0) {
+ kfree(databuf);
+ kfree(dr);
+ }
usb_free_urb(urb);
return rc;
}