This is a note to let you know that I've just added the patch titled

Input: ims-psu - check if CDC union descriptor is sane

to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: input-ims-psu-check-if-cdc-union-descriptor-is-sane.patch and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From ea04efee7635c9120d015dcdeeeb6988130cb67a Mon Sep 17 00:00:00 2001

From: Dmitry Torokhov dmitry.torokhov@gmail.com Date: Sat, 7 Oct 2017 11:07:47 -0700 Subject: Input: ims-psu - check if CDC union descriptor is sane

From: Dmitry Torokhov dmitry.torokhov@gmail.com

commit ea04efee7635c9120d015dcdeeeb6988130cb67a upstream.

Before trying to use CDC union descriptor, try to validate whether that it is sane by checking that intf->altsetting->extra is big enough and that descriptor bLength is not too big and not too small.

Reported-by: Andrey Konovalov andreyknvl@google.com Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Cc: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/input/misc/ims-pcu.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)

--- a/drivers/input/misc/ims-pcu.c +++ b/drivers/input/misc/ims-pcu.c @@ -1635,13 +1635,25 @@ ims_pcu_get_cdc_union_desc(struct usb_in return NULL; }

- while (buflen > 0) { + while (buflen >= sizeof(*union_desc)) { union_desc = (struct usb_cdc_union_desc *)buf;

+ if (union_desc->bLength > buflen) { + dev_err(&intf->dev, "Too large descriptor\n"); + return NULL; + } + if (union_desc->bDescriptorType == USB_DT_CS_INTERFACE && union_desc->bDescriptorSubType == USB_CDC_UNION_TYPE) { dev_dbg(&intf->dev, "Found union header\n"); - return union_desc; + + if (union_desc->bLength >= sizeof(*union_desc)) + return union_desc; + + dev_err(&intf->dev, + "Union descriptor to short (%d vs %zd\n)", + union_desc->bLength, sizeof(*union_desc)); + return NULL; }

buflen -= union_desc->bLength;

Patches currently in stable-queue which might be from dmitry.torokhov@gmail.com are

queue-3.18/input-ims-psu-check-if-cdc-union-descriptor-is-sane.patch