patch "usb: gadgetfs: restrict upper bound on device configuration size" added to usb-linus

patch "usb: gadgetfs: restrict upper bound on device configuration size" added to usb-linus

[gregkh]

This is a note to let you know that I've just added the patch titled

    usb: gadgetfs: restrict upper bound on device configuration size

to my usb git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-linus branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the
next -rc kernel release.

If you have any questions about this process, please let me know.


>From 0994b0a257557e18ee8f0b7c5f0f73fe2b54eec1 Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Tue, 6 Dec 2016 08:36:29 +0100
Subject: usb: gadgetfs: restrict upper bound on device configuration size

Andrey Konovalov reported that we were not properly checking the upper
limit before of a device configuration size before calling
memdup_user(), which could cause some problems.

So set the upper limit to PAGE_SIZE * 4, which should be good enough for
all devices.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
---
 drivers/usb/gadget/legacy/inode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index e8f4102d19df..48f1409b438a 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -1762,7 +1762,8 @@ dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
 	}
 	spin_unlock_irq(&dev->lock);
 
-	if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
+	if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
+	    (len > PAGE_SIZE * 4))
 		return -EINVAL;
 
 	/* we might need to change message format someday */
-- 
2.11.0