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 50327ffdf127e943af5e70da33a5921c0e56714f..e57c5837d2703033a5a4fd2a21e400d7617e9799 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()
     },
 };