From: Theodore Ts'o <tytso@mit.edu>
Date: Wed, 4 Jul 2012 15:22:20 +0000 (-0400)
Subject: usb: feed USB device information to the /dev/random driver
X-Git-Tag: v3.6-rc1~26^2~28
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=b04b3156a20d395a7faa8eed98698d1e17a36000;p=profile%2Fivi%2Fkernel-adaptation-intel-automotive.git

usb: feed USB device information to the /dev/random driver

Send the USB device's serial, product, and manufacturer strings to the
/dev/random driver to help seed its pools.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
---

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 25a7422..7f380ff 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -24,6 +24,7 @@
 #include <linux/kthread.h>
 #include <linux/mutex.h>
 #include <linux/freezer.h>
+#include <linux/random.h>
 
 #include <asm/uaccess.h>
 #include <asm/byteorder.h>
@@ -2173,6 +2174,14 @@ int usb_new_device(struct usb_device *udev)
 	/* Tell the world! */
 	announce_device(udev);
 
+	if (udev->serial)
+		add_device_randomness(udev->serial, strlen(udev->serial));
+	if (udev->product)
+		add_device_randomness(udev->product, strlen(udev->product));
+	if (udev->manufacturer)
+		add_device_randomness(udev->manufacturer,
+				      strlen(udev->manufacturer));
+
 	device_enable_async_suspend(&udev->dev);
 
 	/*