4.9-stable review patch. If anyone has any objections, please let me know. ------------------ 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: