From: Zhao Liu <zhao1....@intel.com>
As the comment in qapi/error, dereferencing @errp requires
ERRP_GUARD():
* = Why, when and how to use ERRP_GUARD() =
*
* Without ERRP_GUARD(), use of the @errp parameter is restricted:
* - It must not be dereferenced, because it may be null.
...
* ERRP_GUARD() lifts these restrictions.
*
* To use ERRP_GUARD(), add it right at the beginning of the function.
* @errp can then be used without worrying about the argument being
* NULL or &error_fatal.
*
* Using it when it's not needed is safe, but please avoid cluttering
* the source with useless code.
But in macfb_nubus_realize(), @errp is dereferenced without
ERRP_GUARD():
ndc->parent_realize(dev, errp);
if (*errp) {
return;
}
Here we check *errp, because the ndc->parent_realize(), as a
DeviceClass.realize() callback, returns void. And since
macfb_nubus_realize(), also as a DeviceClass.realize(), doesn't get the
NULL @errp parameter, it hasn't triggered the bug that dereferencing the
NULL @errp.
To follow the requirement of @errp, add missing ERRP_GUARD() in
macfb_nubus_realize().
Suggested-by: Markus Armbruster <arm...@redhat.com>
Signed-off-by: Zhao Liu <zhao1....@intel.com>
Reviewed-by: Markus Armbruster <arm...@redhat.com>
Message-ID: <20240223085653.1255438-3-zhao1....@linux.intel.com>
Signed-off-by: Thomas Huth <th...@redhat.com>
---
hw/display/macfb.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/hw/display/macfb.c b/hw/display/macfb.c
index 418e99c8e1..1ace341a0f 100644
--- a/hw/display/macfb.c
+++ b/hw/display/macfb.c
@@ -714,6 +714,7 @@ static void macfb_nubus_set_irq(void *opaque, int n, int
level)
static void macfb_nubus_realize(DeviceState *dev, Error **errp)
{
+ ERRP_GUARD();
NubusDevice *nd = NUBUS_DEVICE(dev);
MacfbNubusState *s = NUBUS_MACFB(dev);
MacfbNubusDeviceClass *ndc = NUBUS_MACFB_GET_CLASS(dev);
--
2.44.0
