4.14-stable patches

[thirdparty/kernel/stable-queue.git] / releases / 3.19.2 / usb-usbfs-don-t-leak-kernel-data-in-siginfo.patch

From f0c2b68198589249afd2b1f2c4e8de8c03e19c16 Mon Sep 17 00:00:00 2001
From: Alan Stern <stern@rowland.harvard.edu>
Date: Fri, 13 Feb 2015 10:54:53 -0500
Subject: USB: usbfs: don't leak kernel data in siginfo

From: Alan Stern <stern@rowland.harvard.edu>

commit f0c2b68198589249afd2b1f2c4e8de8c03e19c16 upstream.

When a signal is delivered, the information in the siginfo structure
is copied to userspace.  Good security practice dicatates that the
unused fields in this structure should be initialized to 0 so that
random kernel stack data isn't exposed to the user.  This patch adds
such an initialization to the two places where usbfs raises signals.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Dave Mielke <dave@mielke.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/usb/core/devio.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -501,6 +501,7 @@ static void async_completed(struct urb *
 	as->status = urb->status;
 	signr = as->signr;
 	if (signr) {
+		memset(&sinfo, 0, sizeof(sinfo));
 		sinfo.si_signo = as->signr;
 		sinfo.si_errno = as->status;
 		sinfo.si_code = SI_ASYNCIO;
@@ -2371,6 +2372,7 @@ static void usbdev_remove(struct usb_dev
 		wake_up_all(&ps->wait);
 		list_del_init(&ps->list);
 		if (ps->discsignr) {
+			memset(&sinfo, 0, sizeof(sinfo));
 			sinfo.si_signo = ps->discsignr;
 			sinfo.si_errno = EPIPE;
 			sinfo.si_code = SI_ASYNCIO;