File CVE-2013-4540-qemu.patch of Package xen.481

References: bnc#864801

Subject: zaurus: fix buffer overrun on invalid state load
From: Michael S. Tsirkin mst@redhat.com Thu Apr 3 19:52:13 2014 +0300
Date: Mon May 5 22:15:02 2014 +0200:
Git: 52f91c3723932f8340fe36c8ec8b18a757c37b2b

CVE-2013-4540

Within scoop_gpio_handler_update, if prev_level has a high bit set, then
we get bit > 16 and that causes a buffer overrun.

Since prev_level comes from wire indirectly, this can
happen on invalid state load.

Similarly for gpio_level and gpio_dir.

To fix, limit to 16 bit.

Reported-by: Michael S. Tsirkin <mst@redhat.com>
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>

Index: xen-4.4.1-testing/tools/qemu-xen-dir-remote/hw/gpio/zaurus.c
===================================================================
--- xen-4.4.1-testing.orig/tools/qemu-xen-dir-remote/hw/gpio/zaurus.c
+++ xen-4.4.1-testing/tools/qemu-xen-dir-remote/hw/gpio/zaurus.c
@@ -203,6 +203,15 @@ static bool is_version_0 (void *opaque,
     return version_id == 0;
 }
 
+static bool vmstate_scoop_validate(void *opaque, int version_id)
+{
+    ScoopInfo *s = opaque;
+
+    return !(s->prev_level & 0xffff0000) &&
+        !(s->gpio_level & 0xffff0000) &&
+        !(s->gpio_dir & 0xffff0000);
+}
+
 static const VMStateDescription vmstate_scoop_regs = {
     .name = "scoop",
     .version_id = 1,
@@ -215,6 +224,7 @@ static const VMStateDescription vmstate_
         VMSTATE_UINT32(gpio_level, ScoopInfo),
         VMSTATE_UINT32(gpio_dir, ScoopInfo),
         VMSTATE_UINT32(prev_level, ScoopInfo),
+        VMSTATE_VALIDATE("irq levels are 16 bit", vmstate_scoop_validate),
         VMSTATE_UINT16(mcr, ScoopInfo),
         VMSTATE_UINT16(cdr, ScoopInfo),
         VMSTATE_UINT16(ccr, ScoopInfo),