File CVE-2013-4534-qemuu-openpic-buffer-overrun-on-incoming-migration.patch of Package xen.7317

References: bsc#964452 CVE-2013-4534

Subject: openpic: avoid buffer overrun on incoming migration
From: Michael Roth mdroth@linux.vnet.ibm.com Mon Apr 28 16:08:17 2014 +0300
Date: Mon May 5 22:15:03 2014 +0200:
Git: 73d963c0a75cb99c6aaa3f6f25e427aa0b35a02e

CVE-2013-4534

opp->nb_cpus is read from the wire and used to determine how many
IRQDest elements to read into opp->dst[]. If the value exceeds the
length of opp->dst[], MAX_CPU, opp->dst[] can be overrun with arbitrary
data from the wire.

Fix this by failing migration if the value read from the wire exceeds
MAX_CPU.

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

Index: xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/intc/openpic.c
===================================================================
--- xen-4.4.4-testing.orig/tools/qemu-xen-dir-remote/hw/intc/openpic.c
+++ xen-4.4.4-testing/tools/qemu-xen-dir-remote/hw/intc/openpic.c
@@ -41,6 +41,7 @@
 #include "hw/sysbus.h"
 #include "hw/pci/msi.h"
 #include "qemu/bitops.h"
+#include "qapi/qmp/qerror.h"
 
 //#define DEBUG_OPENPIC
 
@@ -1416,7 +1417,7 @@ static void openpic_load_IRQ_queue(QEMUF
 static int openpic_load(QEMUFile* f, void *opaque, int version_id)
 {
     OpenPICState *opp = (OpenPICState *)opaque;
-    unsigned int i;
+    unsigned int i, nb_cpus;
 
     if (version_id != 1) {
         return -EINVAL;
@@ -1428,7 +1429,11 @@ static int openpic_load(QEMUFile* f, voi
     qemu_get_be32s(f, &opp->spve);
     qemu_get_be32s(f, &opp->tfrr);
 
-    qemu_get_be32s(f, &opp->nb_cpus);
+    qemu_get_be32s(f, &nb_cpus);
+    if (opp->nb_cpus != nb_cpus) {
+        return -EINVAL;
+    }
+    assert(nb_cpus > 0 && nb_cpus <= MAX_CPU);
 
     for (i = 0; i < opp->nb_cpus; i++) {
         qemu_get_sbe32s(f, &opp->dst[i].ctpr);
@@ -1567,6 +1572,13 @@ static void openpic_realize(DeviceState
         {NULL}
     };
 
+    if (opp->nb_cpus > MAX_CPU) {
+        error_set(errp, QERR_PROPERTY_VALUE_OUT_OF_RANGE,
+                  TYPE_OPENPIC, "nb_cpus", (uint64_t)opp->nb_cpus,
+                  (uint64_t)0, (uint64_t)MAX_CPU);
+        return;
+    }
+
     switch (opp->model) {
     case OPENPIC_MODEL_FSL_MPIC_20:
     default: