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 <m...@redhat.com>
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
hw/gpio/zaurus.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/hw/gpio/zaurus.c b/hw/gpio/zaurus.c
index dc79a8b..8e2ce04 100644
--- a/hw/gpio/zaurus.c
+++ b/hw/gpio/zaurus.c
@@ -203,6 +203,15 @@ static bool is_version_0 (void *opaque, int version_id)
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_scoop_regs = {
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),
--
MST
