lkml.org 
[lkml]   [2016]   [Mar]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.2.y-ckt 015/218] USB: cdc-acm: more sanity checking
Date
4.2.8-ckt7 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Oliver Neukum <oneukum@suse.com>

commit 8835ba4a39cf53f705417b3b3a94eb067673f2c9 upstream.

An attack has become available which pretends to be a quirky
device circumventing normal sanity checks and crashes the kernel
by an insufficient number of interfaces. This patch adds a check
to the code path for quirky devices.

Signed-off-by: Oliver Neukum <ONeukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/usb/class/cdc-acm.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index fa4e239..d37fdcc 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1114,6 +1114,9 @@ static int acm_probe(struct usb_interface *intf,
if (quirks == NO_UNION_NORMAL) {
data_interface = usb_ifnum_to_if(usb_dev, 1);
control_interface = usb_ifnum_to_if(usb_dev, 0);
+ /* we would crash */
+ if (!data_interface || !control_interface)
+ return -ENODEV;
goto skip_normal_probe;
}

--
2.7.4
\
 
 \ /
  Last update: 2016-03-31 22:41    [W:0.696 / U:0.296 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site