0008-hpet-fix-buffer-overrun-on-invalid-state-load.patch

   1 From 5e0e0a12887c9e70356c23d20b08b08eabd4a6df Mon Sep 17 00:00:00 2001
   2 From: "Michael S. Tsirkin" <mst@redhat.com>
   3 Date: Thu, 3 Apr 2014 19:51:23 +0300
   4 Subject: [PATCH] hpet: fix buffer overrun on invalid state load
   5
   6 CVE-2013-4527 hw/timer/hpet.c buffer overrun
   7
   8 hpet is a VARRAY with a uint8 size but static array of 32
   9
  10 To fix, make sure num_timers is valid using VMSTATE_VALID hook.
  11
  12 Reported-by: Anthony Liguori <anthony@codemonkey.ws>
  13 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
  14 Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  15 Signed-off-by: Juan Quintela <quintela@redhat.com>
  16 (cherry picked from commit 3f1c49e2136fa08ab1ef3183fd55def308829584)
  17 ---
  18  hw/timer/hpet.c | 13 +++++++++++++
  19  1 file changed, 13 insertions(+)
  20
  21 diff --git a/hw/timer/hpet.c b/hw/timer/hpet.c
  22 index e15d6bc..2792f89 100644
  23 --- a/hw/timer/hpet.c
  24 +++ b/hw/timer/hpet.c
  25 @@ -239,6 +239,18 @@ static int hpet_pre_load(void *opaque)
  26      return 0;
  27  }
  28
  29 +static bool hpet_validate_num_timers(void *opaque, int version_id)
  30 +{
  31 +    HPETState *s = opaque;
  32 +
  33 +    if (s->num_timers < HPET_MIN_TIMERS) {
  34 +        return false;
  35 +    } else if (s->num_timers > HPET_MAX_TIMERS) {
  36 +        return false;
  37 +    }
  38 +    return true;
  39 +}
  40 +
  41  static int hpet_post_load(void *opaque, int version_id)
  42  {
  43      HPETState *s = opaque;
  44 @@ -307,6 +319,7 @@ static const VMStateDescription vmstate_hpet = {
  45          VMSTATE_UINT64(isr, HPETState),
  46          VMSTATE_UINT64(hpet_counter, HPETState),
  47          VMSTATE_UINT8_V(num_timers, HPETState, 2),
  48 +        VMSTATE_VALIDATE("num_timers in range", hpet_validate_num_timers),
  49          VMSTATE_STRUCT_VARRAY_UINT8(timer, HPETState, num_timers, 0,
  50                                      vmstate_hpet_timer, HPETTimer),
  51          VMSTATE_END_OF_LIST()