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>
(cherry picked from commit ae2158ad6ce0845b2fae2a22aa7f19c0d7a71ce5)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index bfe633f3a5e3bf6824f5c88cbdca5c571f513d01..457a7a1c406aa57c476ebdbcae1689889d08b647 100644 (file)
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -1293,7 +1293,7 @@ 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()
     },
 };