From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36351) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dxEGN-0003Sk-6h for qemu-devel@nongnu.org; Wed, 27 Sep 2017 11:28:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dxEGJ-0003nE-27 for qemu-devel@nongnu.org; Wed, 27 Sep 2017 11:28:39 -0400 From: Thomas Huth Date: Wed, 27 Sep 2017 17:28:26 +0200 Message-Id: <1506526106-30971-1-git-send-email-thuth@redhat.com> Subject: [Qemu-devel] [PATCH 1/1] hw/usb/bus: Remove bad object_unparent() from usb_try_create_simple() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Gerd Hoffmann , qemu-devel@nongnu.org Cc: Paolo Bonzini , qemu-stable@nongnu.org Valgrind detects an invalid read operation when hot-plugging of an USB device fails: $ valgrind x86_64-softmmu/qemu-system-x86_64 -device usb-ehci -nographic -S ==30598== Memcheck, a memory error detector ==30598== Copyright (C) 2002-2015, and GNU GPL'd, by Julian Seward et al. ==30598== Using Valgrind-3.12.0 and LibVEX; rerun with -h for copyright info ==30598== Command: x86_64-softmmu/qemu-system-x86_64 -device usb-ehci -nographic -S ==30598== QEMU 2.10.50 monitor - type 'help' for more information (qemu) device_add usb-tablet (qemu) device_add usb-tablet (qemu) device_add usb-tablet (qemu) device_add usb-tablet (qemu) device_add usb-tablet (qemu) device_add usb-tablet ==30598== Invalid read of size 8 ==30598== at 0x60EF50: object_unparent (object.c:445) ==30598== by 0x580F0D: usb_try_create_simple (bus.c:346) ==30598== by 0x581BEB: usb_claim_port (bus.c:451) ==30598== by 0x582310: usb_qdev_realize (bus.c:257) ==30598== by 0x4CB399: device_set_realized (qdev.c:914) ==30598== by 0x60E26D: property_set_bool (object.c:1886) ==30598== by 0x61235E: object_property_set_qobject (qom-qobject.c:27) ==30598== by 0x61000F: object_property_set_bool (object.c:1162) ==30598== by 0x4567C3: qdev_device_add (qdev-monitor.c:630) ==30598== by 0x456D52: qmp_device_add (qdev-monitor.c:807) ==30598== by 0x470A99: hmp_device_add (hmp.c:1933) ==30598== by 0x3679C3: handle_hmp_command (monitor.c:3123) The object_unparent() here is not necessary anymore since commit 69382d8b3e8600b3 ("qdev: Fix object reference leak in case device.realize() fails"), so let's remove it now. Suggested-by: Paolo Bonzini Signed-off-by: Thomas Huth --- hw/usb/bus.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/hw/usb/bus.c b/hw/usb/bus.c index d910f84..e56dc33 100644 --- a/hw/usb/bus.c +++ b/hw/usb/bus.c @@ -341,9 +341,7 @@ static USBDevice *usb_try_create_simple(USBBus *bus, const char *name, object_property_set_bool(OBJECT(dev), true, "realized", &err); if (err) { error_propagate(errp, err); - error_prepend(errp, "Failed to initialize USB device '%s': ", - name); - object_unparent(OBJECT(dev)); + error_prepend(errp, "Failed to initialize USB device '%s': ", name); return NULL; } return dev; -- 1.8.3.1