--- /dev/null
+From 47bb117911b051bbc90764a8bff96543cbd2005f Mon Sep 17 00:00:00 2001
+From: Alistair Strachan <astrachan@google.com>
+Date: Tue, 18 Dec 2018 20:32:48 -0500
+Subject: media: uvcvideo: Fix 'type' check leading to overflow
+
+From: Alistair Strachan <astrachan@google.com>
+
+commit 47bb117911b051bbc90764a8bff96543cbd2005f upstream.
+
+When initially testing the Camera Terminal Descriptor wTerminalType
+field (buffer[4]), no mask is used. Later in the function, the MSB is
+overloaded to store the descriptor subtype, and so a mask of 0x7fff
+is used to check the type.
+
+If a descriptor is specially crafted to set this overloaded bit in the
+original wTerminalType field, the initial type check will fail (falling
+through, without adjusting the buffer size), but the later type checks
+will pass, assuming the buffer has been made suitably large, causing an
+overflow.
+
+Avoid this problem by checking for the MSB in the wTerminalType field.
+If the bit is set, assume the descriptor is bad, and abort parsing it.
+
+Originally reported here:
+https://groups.google.com/forum/#!topic/syzkaller/Ot1fOE6v1d8
+A similar (non-compiling) patch was provided at that time.
+
+Reported-by: syzbot <syzkaller@googlegroups.com>
+Signed-off-by: Alistair Strachan <astrachan@google.com>
+Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/media/usb/uvc/uvc_driver.c | 14 +++++++++++---
+ 1 file changed, 11 insertions(+), 3 deletions(-)
+
+--- a/drivers/media/usb/uvc/uvc_driver.c
++++ b/drivers/media/usb/uvc/uvc_driver.c
+@@ -1065,11 +1065,19 @@ static int uvc_parse_standard_control(st
+ return -EINVAL;
+ }
+
+- /* Make sure the terminal type MSB is not null, otherwise it
+- * could be confused with a unit.
++ /*
++ * Reject invalid terminal types that would cause issues:
++ *
++ * - The high byte must be non-zero, otherwise it would be
++ * confused with a unit.
++ *
++ * - Bit 15 must be 0, as we use it internally as a terminal
++ * direction flag.
++ *
++ * Other unknown types are accepted.
+ */
+ type = get_unaligned_le16(&buffer[4]);
+- if ((type & 0xff00) == 0) {
++ if ((type & 0x7f00) == 0 || (type & 0x8000) != 0) {
+ uvc_trace(UVC_TRACE_DESCR, "device %d videocontrol "
+ "interface %d INPUT_TERMINAL %d has invalid "
+ "type 0x%04x, skipping\n", udev->devnum,