[PATCH 3.16 084/134] usb: misc: legousbtower: Fix buffers on stack

Ben Hutchings
2017-08-18T13:13:20Z

From: Maksim Salau <maksim.salau@gmail.com>

commit 942a48730faf149ccbf3e12ac718aee120bb3529 upstream.

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.salau@gmail.com>
Tested-by: Alfredo Rafael Vicente Boix <alviboi@gmail.com>;
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/misc/legousbtower.c | 37 +++++++++++++++++++++++++++----------
1 file changed, 27 insertions(+), 10 deletions(-)

--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -317,9 +317,16 @@ static int tower_open (struct inode *ino
int subminor;
int retval = 0;
struct usb_interface *interface;
- struct tower_reset_reply reset_reply;
+ struct tower_reset_reply *reset_reply;
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 *ino
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 @@ unlock_exit:
mutex_unlock(&dev->lock);

exit:
+ kfree(reset_reply);
return retval;
}

@@ -808,7 +816,7 @@ static int tower_probe (struct usb_inter
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;
@@ -898,6 +906,13 @@ static int tower_probe (struct usb_inter
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),
@@ -905,18 +920,19 @@ static int tower_probe (struct usb_inter
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");
retval = result;
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));
+ 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));

/* we can register the device now, as it is ready */
usb_set_intfdata (interface, dev);
@@ -940,6 +956,7 @@ exit:
return retval;

error:
+ kfree(get_version_reply);
tower_delete(dev);
return retval;
}