This is a note to let you know that I've just added the patch titled USB: cdc-acm: more sanity checking to the 4.4-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: usb-cdc-acm-more-sanity-checking.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 8835ba4a39cf53f705417b3b3a94eb067673f2c9 Mon Sep 17 00:00:00 2001 From: Oliver Neukum <oneukum@xxxxxxxx> Date: Tue, 15 Mar 2016 10:14:04 +0100 Subject: USB: cdc-acm: more sanity checking From: Oliver Neukum <oneukum@xxxxxxxx> 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@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/cdc-acm.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1114,6 +1114,9 @@ static int acm_probe(struct usb_interfac 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; } Patches currently in stable-queue which might be from oneukum@xxxxxxxx are queue-4.4/usb-cdc-acm-more-sanity-checking.patch queue-4.4/usb-mct_u232-add-sanity-checking-in-probe.patch queue-4.4/usb-digi_acceleport-do-sanity-checking-for-the-number-of-ports.patch queue-4.4/usb-cypress_m8-add-endpoint-sanity-check.patch queue-4.4/usb-retry-reset-if-a-device-times-out.patch queue-4.4/usb-hub-fix-a-typo-in-hub_port_init-leading-to-wrong-logic.patch queue-4.4/usb-usb_driver_claim_interface-add-sanity-checking.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html