hpet: fix buffer overrun on invalid state load

CVE-2013-4527 hw/timer/hpet.c buffer overrun

hpet is a VARRAY with a uint8 size but static array of 32

To fix, make sure num_timers is valid using VMSTATE_VALID hook.

Reported-by: Anthony Liguori <anthony@codemonkey.ws>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2014-04-03 19:51:23 +03:00 committed by Juan Quintela
parent ae2158ad6c
commit 3f1c49e213

View File

@ -239,6 +239,18 @@ static int hpet_pre_load(void *opaque)
return 0;
}
static bool hpet_validate_num_timers(void *opaque, int version_id)
{
HPETState *s = opaque;
if (s->num_timers < HPET_MIN_TIMERS) {
return false;
} else if (s->num_timers > HPET_MAX_TIMERS) {
return false;
}
return true;
}
static int hpet_post_load(void *opaque, int version_id)
{
HPETState *s = opaque;
@ -307,6 +319,7 @@ static const VMStateDescription vmstate_hpet = {
VMSTATE_UINT64(isr, HPETState),
VMSTATE_UINT64(hpet_counter, HPETState),
VMSTATE_UINT8_V(num_timers, HPETState, 2),
VMSTATE_VALIDATE("num_timers in range", hpet_validate_num_timers),
VMSTATE_STRUCT_VARRAY_UINT8(timer, HPETState, num_timers, 0,
vmstate_hpet_timer, HPETTimer),
VMSTATE_END_OF_LIST()