From 5aa4a6417b0f7acbfd7f4c21dca26293bc3d9348 Mon Sep 17 00:00:00 2001 From: Zhao Liu Date: Fri, 23 Feb 2024 16:56:48 +0800 Subject: [PATCH] hw/display/macfb: Fix missing ERRP_GUARD() in macfb_nubus_realize() 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 Signed-off-by: Zhao Liu Reviewed-by: Markus Armbruster Message-Id: <20240223085653.1255438-3-zhao1.liu@linux.intel.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- 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);