Allocate buffers on HEAP instead of STACK for local structures
that are to be received using usb_control_msg().

Signed-off-by: Maksim Salau <maksim.sa...@gmail.com>
---

I took the liberty to fix the module if Greg don't mind.
It is to be applied on vanilla v4.10.12 (without Greg's patch).

Changes compared to Greg's version:
* fixed tower_reset() which is used in the open callback;
* better deallocation handling in case of failures.

BTW, using the following grep magic I've discovered 3 more
placed to be fixed:

$ grep --include=*.c -PIzor 
"(?s)usb_control_msg\s*\([^;]+,\s*&?(\w+)\s*,\s*sizeof\(\1\)[^;]+\);[^\n]*\n"
video/fbdev/udlfb.c:usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
                        NR_USB_REQUEST_CHANNEL,
                        (USB_DIR_OUT | USB_TYPE_VENDOR), 0, 0,
                        set_def_chn, sizeof(set_def_chn), USB_CTRL_SET_TIMEOUT);
net/can/usb/gs_usb.c:usb_control_msg(interface_to_usbdev(dev->iface),
                             usb_sndctrlpipe(interface_to_usbdev(dev->iface),
                                             0),
                             GS_USB_BREQ_IDENTIFY,
                             USB_DIR_OUT | USB_TYPE_VENDOR |
                             USB_RECIP_INTERFACE,
                             dev->channel,
                             0,
                             &imode,
                             sizeof(imode),
                             100);
net/wireless/intersil/orinoco/orinoco_usb.c:usb_control_msg(upriv->udev,
                               usb_sndctrlpipe(upriv->udev, 0),
                               EZUSB_REQUEST_FW_TRANS,
                               USB_TYPE_VENDOR | USB_RECIP_DEVICE |
                               USB_DIR_OUT, EZUSB_CPUCS_REG, 0, &res_val,
                               sizeof(res_val), DEF_TIMEOUT);

Here are 1 case with a local buffer and 2 cases with local variables
sent with usb_control_msg. I'll prepare fixes for those issues shortly.

Best regards,
Maksim.


 drivers/usb/misc/legousbtower.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index 322a042..5747615c 100644
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -317,9 +317,16 @@ static int tower_open (struct inode *inode, struct file 
*file)
        int subminor;
        int retval = 0;
        struct usb_interface *interface;
-       struct tower_reset_reply reset_reply;
+       struct tower_reset_reply *reset_reply = NULL;
        int result;
 
+       reset_reply = kmalloc(sizeof(*reset_reply), GFP_KERNEL);
+
+       if (!reset_reply) {
+               retval = -ENOMEM;
+               goto exit;
+       }
+
        nonseekable_open(inode, file);
        subminor = iminor(inode);
 
@@ -364,8 +371,8 @@ static int tower_open (struct inode *inode, struct file 
*file)
                                  USB_TYPE_VENDOR | USB_DIR_IN | 
USB_RECIP_DEVICE,
                                  0,
                                  0,
-                                 &reset_reply,
-                                 sizeof(reset_reply),
+                                 reset_reply,
+                                 sizeof(*reset_reply),
                                  1000);
        if (result < 0) {
                dev_err(&dev->udev->dev,
@@ -406,6 +413,7 @@ static int tower_open (struct inode *inode, struct file 
*file)
        mutex_unlock(&dev->lock);
 
 exit:
+       kfree(reset_reply);
        return retval;
 }
 
@@ -808,7 +816,7 @@ static int tower_probe (struct usb_interface *interface, 
const struct usb_device
        struct lego_usb_tower *dev = NULL;
        struct usb_host_interface *iface_desc;
        struct usb_endpoint_descriptor* endpoint;
-       struct tower_get_version_reply get_version_reply;
+       struct tower_get_version_reply *get_version_reply = NULL;
        int i;
        int retval = -ENOMEM;
        int result;
@@ -886,6 +894,13 @@ static int tower_probe (struct usb_interface *interface, 
const struct usb_device
        dev->interrupt_in_interval = interrupt_in_interval ? 
interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
        dev->interrupt_out_interval = interrupt_out_interval ? 
interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
 
+       get_version_reply = kmalloc(sizeof(*get_version_reply), GFP_KERNEL);
+
+       if (!get_version_reply) {
+               retval = -ENOMEM;
+               goto error;
+       }
+
        /* get the firmware version and log it */
        result = usb_control_msg (udev,
                                  usb_rcvctrlpipe(udev, 0),
@@ -893,8 +908,8 @@ static int tower_probe (struct usb_interface *interface, 
const struct usb_device
                                  USB_TYPE_VENDOR | USB_DIR_IN | 
USB_RECIP_DEVICE,
                                  0,
                                  0,
-                                 &get_version_reply,
-                                 sizeof(get_version_reply),
+                                 get_version_reply,
+                                 sizeof(*get_version_reply),
                                  1000);
        if (result < 0) {
                dev_err(idev, "LEGO USB Tower get version control request 
failed\n");
@@ -902,9 +917,9 @@ static int tower_probe (struct usb_interface *interface, 
const struct usb_device
                goto error;
        }
        dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d "
-                "build %d\n", get_version_reply.major,
-                get_version_reply.minor,
-                le16_to_cpu(get_version_reply.build_no));
+                "build %d\n", get_version_reply->major,
+                get_version_reply->minor,
+                le16_to_cpu(get_version_reply->build_no));
 
        /* we can register the device now, as it is ready */
        usb_set_intfdata (interface, dev);
@@ -928,6 +943,7 @@ static int tower_probe (struct usb_interface *interface, 
const struct usb_device
        return retval;
 
 error:
+       kfree(get_version_reply);
        tower_delete(dev);
        return retval;
 }
-- 
2.9.3

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