releases/4.14.53/video-uvesafb-fix-integer-overflow-in-allocation.patch

   1 From 9f645bcc566a1e9f921bdae7528a01ced5bc3713 Mon Sep 17 00:00:00 2001
   2 From: Kees Cook <keescook@chromium.org>
   3 Date: Fri, 11 May 2018 18:24:12 +1000
   4 Subject: video: uvesafb: Fix integer overflow in allocation
   5
   6 From: Kees Cook <keescook@chromium.org>
   7
   8 commit 9f645bcc566a1e9f921bdae7528a01ced5bc3713 upstream.
   9
  10 cmap->len can get close to INT_MAX/2, allowing for an integer overflow in
  11 allocation. This uses kmalloc_array() instead to catch the condition.
  12
  13 Reported-by: Dr Silvio Cesare of InfoSect <silvio.cesare@gmail.com>
  14 Fixes: 8bdb3a2d7df48 ("uvesafb: the driver core")
  15 Cc: stable@vger.kernel.org
  16 Signed-off-by: Kees Cook <keescook@chromium.org>
  17 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  18
  19 ---
  20  drivers/video/fbdev/uvesafb.c |    3 ++-
  21  1 file changed, 2 insertions(+), 1 deletion(-)
  22
  23 --- a/drivers/video/fbdev/uvesafb.c
  24 +++ b/drivers/video/fbdev/uvesafb.c
  25 @@ -1044,7 +1044,8 @@ static int uvesafb_setcmap(struct fb_cma
  26                     info->cmap.len || cmap->start < info->cmap.start)
  27                         return -EINVAL;
  28
  29 -               entries = kmalloc(sizeof(*entries) * cmap->len, GFP_KERNEL);
  30 +               entries = kmalloc_array(cmap->len, sizeof(*entries),
  31 +                                       GFP_KERNEL);
  32                 if (!entries)
  33                         return -ENOMEM;
  34