releases/4.9.30/digitv-limit-messages-to-buffer-size.patch

   1 From 821117dc21083a99dd99174c10848d70ff43de29 Mon Sep 17 00:00:00 2001
   2 From: Alyssa Milburn <amilburn@zall.org>
   3 Date: Sat, 1 Apr 2017 14:33:42 -0300
   4 Subject: [media] digitv: limit messages to buffer size
   5
   6 From: Alyssa Milburn <amilburn@zall.org>
   7
   8 commit 821117dc21083a99dd99174c10848d70ff43de29 upstream.
   9
  10 Return an error rather than memcpy()ing beyond the end of the buffer.
  11 Internal callers use appropriate sizes, but digitv_i2c_xfer may not.
  12
  13 Signed-off-by: Alyssa Milburn <amilburn@zall.org>
  14 Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
  15 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  16
  17 ---
  18  drivers/media/usb/dvb-usb/digitv.c |    3 +++
  19  1 file changed, 3 insertions(+)
  20
  21 --- a/drivers/media/usb/dvb-usb/digitv.c
  22 +++ b/drivers/media/usb/dvb-usb/digitv.c
  23 @@ -33,6 +33,9 @@ static int digitv_ctrl_msg(struct dvb_us
  24
  25         wo = (rbuf == NULL || rlen == 0); /* write-only */
  26
  27 +       if (wlen > 4 || rlen > 4)
  28 +               return -EIO;
  29 +
  30         memset(st->sndbuf, 0, 7);
  31         memset(st->rcvbuf, 0, 7);
  32