This is a note to let you know that I've just added the patch titled
cdc-acm: fix possible invalid access when processing notification
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cdc-acm-fix-possible-invalid-access-when-processing-notification.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 1bb9914e1730417d530de9ed37e59efdc647146b Mon Sep 17 00:00:00 2001
From: Tobias Herzog <t-herzog@xxxxxx>
Date: Thu, 30 Mar 2017 22:15:10 +0200
Subject: cdc-acm: fix possible invalid access when processing notification
From: Tobias Herzog <t-herzog@xxxxxx>
commit 1bb9914e1730417d530de9ed37e59efdc647146b upstream.
Notifications may only be 8 bytes long. Accessing the 9th and
10th byte of unimplemented/unknown notifications may be insecure.
Also check the length of known notifications before accessing anything
behind the 8th byte.
Signed-off-by: Tobias Herzog <t-herzog@xxxxxx>
Acked-by: Oliver Neukum <oneukum@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/class/cdc-acm.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -311,6 +311,12 @@ static void acm_ctrl_irq(struct urb *urb
break;
case USB_CDC_NOTIFY_SERIAL_STATE:
+ if (le16_to_cpu(dr->wLength) != 2) {
+ dev_dbg(&acm->control->dev,
+ "%s - malformed serial state\n", __func__);
+ break;
+ }
+
newctrl = get_unaligned_le16(data);
if (!acm->clocal && (acm->ctrlin & ~newctrl & ACM_CTRL_DCD)) {
@@ -347,11 +353,10 @@ static void acm_ctrl_irq(struct urb *urb
default:
dev_dbg(&acm->control->dev,
- "%s - unknown notification %d received: index %d "
- "len %d data0 %d data1 %d\n",
+ "%s - unknown notification %d received: index %d len %d\n",
__func__,
- dr->bNotificationType, dr->wIndex,
- dr->wLength, data[0], data[1]);
+ dr->bNotificationType, dr->wIndex, dr->wLength);
+
break;
}
exit:
Patches currently in stable-queue which might be from t-herzog@xxxxxx are
queue-4.9/cdc-acm-fix-possible-invalid-access-when-processing-notification.patch