xen/CVE-2013-4540-qemu.patch

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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),