ahci: fix buffer overrun on invalid state load

CVE-2013-4526

Within hw/ide/ahci.c, VARRAY refers to ports which is also loaded.  So
we use the old version of ports to read the array but then allow any
value for ports.  This can cause the code to overflow.

There's no reason to migrate ports - it never changes.
So just make sure it matches.

Reported-by: Anthony Liguori <anthony@codemonkey.ws>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>

diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index bba150fd7423d981844cbf776c982b28b151b07a..7c62cc7f1c76ab74730c23a9ad1ec4547c3fd601 100644 (file)
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -1281,7 +1281,7 @@ const VMStateDescription vmstate_ahci = {
         VMSTATE_UINT32(control_regs.impl, AHCIState),
         VMSTATE_UINT32(control_regs.version, AHCIState),
         VMSTATE_UINT32(idp_index, AHCIState),
-        VMSTATE_INT32(ports, AHCIState),
+        VMSTATE_INT32_EQUAL(ports, AHCIState),
         VMSTATE_END_OF_LIST()
     },
 };