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authorMichael S. Tsirkin <mst@redhat.com>2014-04-03 19:51:23 +0300
committerJuan Quintela <quintela@redhat.com>2014-05-05 22:15:02 +0200
commit3f1c49e2136fa08ab1ef3183fd55def308829584 (patch)
tree01e28bcbada1f1a759655926234448b5c6d8d0b0 /hw/timer/hpet.c
parentae2158ad6ce0845b2fae2a22aa7f19c0d7a71ce5 (diff)
downloadfocaccia-qemu-3f1c49e2136fa08ab1ef3183fd55def308829584.tar.gz
focaccia-qemu-3f1c49e2136fa08ab1ef3183fd55def308829584.zip
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>
Diffstat (limited to 'hw/timer/hpet.c')
-rw-r--r--hw/timer/hpet.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/hw/timer/hpet.c b/hw/timer/hpet.c
index e15d6bcac7..2792f89c66 100644
--- a/hw/timer/hpet.c
+++ b/hw/timer/hpet.c
@@ -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()