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 my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-testing 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 be merged to the usb-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>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
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>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/class/cdc-acm.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 00d55ba8983f..cdabe76960bc 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -323,6 +323,12 @@ 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)) {
@@ -359,11 +365,10 @@ 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:
--
2.12.1