debian/patches/CVE-2014-8xxx/0003-dix-integer-overflow-in-GetHosts-CVE-2014-8092-2-4.patch

   1 From 2f605f86acec5ce853f764c41f8c737154a274f5 Mon Sep 17 00:00:00 2001
   2 From: Alan Coopersmith <alan.coopersmith@oracle.com>
   3 Date: Mon, 6 Jan 2014 23:30:14 -0800
   4 Subject: [PATCH 03/33] dix: integer overflow in GetHosts() [CVE-2014-8092
   5  2/4]
   6
   7 GetHosts() iterates over all the hosts it has in memory, and copies
   8 them to a buffer. The buffer length is calculated by iterating over
   9 all the hosts and adding up all of their combined length. There is a
  10 potential integer overflow, if there are lots and lots of hosts (with
  11 a combined length of > ~4 gig). This should be possible by repeatedly
  12 calling ProcChangeHosts() on 64bit machines with enough memory.
  13
  14 This patch caps the list at 1mb, because multi-megabyte hostname
  15 lists for X access control are insane.
  16
  17 Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
  18 Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
  19 Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
  20 ---
  21  os/access.c |    6 ++++++
  22  1 file changed, 6 insertions(+)
  23
  24 Index: xorg-server-1.16.0/os/access.c
  25 ===================================================================
  26 --- xorg-server-1.16.0.orig/os/access.c 2014-12-04 11:11:43.752542885 -0500
  27 +++ xorg-server-1.16.0/os/access.c      2014-12-04 11:11:43.748542843 -0500
  28 @@ -1323,6 +1323,10 @@
  29      for (host = validhosts; host; host = host->next) {
  30          nHosts++;
  31          n += pad_to_int32(host->len) + sizeof(xHostEntry);
  32 +        /* Could check for INT_MAX, but in reality having more than 1mb of
  33 +           hostnames in the access list is ridiculous */
  34 +        if (n >= 1048576)
  35 +            break;
  36      }
  37      if (n) {
  38          *data = ptr = malloc(n);
  39 @@ -1331,6 +1335,8 @@
  40          }
  41          for (host = validhosts; host; host = host->next) {
  42              len = host->len;
  43 +            if ((ptr + sizeof(xHostEntry) + len) > (data + n))
  44 +                break;
  45              ((xHostEntry *) ptr)->family = host->family;
  46              ((xHostEntry *) ptr)->length = len;
  47              ptr += sizeof(xHostEntry);