[PATCH 3.16 055/134] [media] zr364xx: enforce minimum size when reading header

Ben Hutchings
2017-08-18T13:15:46Z

From: Alyssa Milburn <amilburn@zall.org>

commit ee0fe833d96793853335844b6d99fb76bd12cbeb upstream.

This code copies actual_length-128 bytes from the header, which will
underflow if the received buffer is too small.

Signed-off-by: Alyssa Milburn <amilburn@zall.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/media/usb/zr364xx/zr364xx.c | 8 ++++++++
1 file changed, 8 insertions(+)

--- a/drivers/media/usb/zr364xx/zr364xx.c
+++ b/drivers/media/usb/zr364xx/zr364xx.c
@@ -605,6 +605,14 @@ static int zr364xx_read_video_callback(s
ptr = pdest = frm->lpvbits;

if (frm->ulState == ZR364XX_READ_IDLE) {
+ if (purb->actual_length < 128) {
+ /* header incomplete */
+ dev_info(&cam->udev->dev,
+ "%s: buffer (%d bytes) too small to hold jpeg header. Discarding.\n",
+ __func__, purb->actual_length);
+ return -EINVAL;
+ }
+
frm->ulState = ZR364XX_READ_FRAME;
frm->cur_size = 0;