From: Alyssa Milburn <amilburn@zall.org>
Date: Sat, 1 Apr 2017 17:34:08 +0000 (-0300)
Subject: zr364xx: enforce minimum size when reading header
X-Git-Tag: release-20171130_firefly~4^2~100^2~1^2~7^2~29
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e5a9ebb4387aad53a3a81aa634734e3edcca8784;p=firefly-linux-kernel-4.4.55.git

zr364xx: enforce minimum size when reading header

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/media/usb/zr364xx/zr364xx.c b/drivers/media/usb/zr364xx/zr364xx.c
index 7433ba5c4bad..fd6a3b36208e 100644
--- a/drivers/media/usb/zr364xx/zr364xx.c
+++ b/drivers/media/usb/zr364xx/zr364xx.c
@@ -604,6 +604,14 @@ static int zr364xx_read_video_callback(struct zr364xx_camera *cam,
 	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;