object_property_set_bool(OBJECT(dev), true, "realized", &err) in pci_nic_init_nofail may release the object if device fails to initialize which leads to use-after-free in error handling block. qdev_init_nofail does the same thing while holding the reference.
(gdb) run -net nic qemu-system-x86_64: failed to find romfile "efi-e1000.rom" Program received signal SIGSEGV, Segmentation fault. object_unparent (obj=0x7fffe96a0010) at qom/object.c:440 440 in qom/object.c (gdb) bt #0 object_unparent (obj=0x7fffe96a0010) at qom/object.c:440 #1 0x000055555598c30d in pci_nic_init_nofail (nd=0x55555616b460 <nd_table>, rootbus=0x5555567ed990, default_model=<optimized out>, default_devaddr=<optimized out>) at hw/pci/pci.c:1812 #2 0x00005555557ff52c in pc_nic_init (isa_bus=0x55555733c610, pci_bus=0x5555567ed990) at hw/i386/pc.c:1634 #3 0x00005555558021ad in pc_init1 (machine=0x55555661ee10, pci_type=0x555555c1a523 "i440FX", host_type=0x555555ba564e "i440FX-pcihost") at hw/i386/pc_piix.c:241 #4 0x00005555557519cb in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4481 Signed-off-by: Alex Kompel <bar...@gmail.com> --- hw/pci/pci.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/hw/pci/pci.c b/hw/pci/pci.c index 24fae16..2fd1b9e 100644 --- a/hw/pci/pci.c +++ b/hw/pci/pci.c @@ -1805,13 +1805,7 @@ PCIDevice *pci_nic_init_nofail(NICInfo *nd, PCIBus *rootbus, pci_dev = pci_create(bus, devfn, pci_nic_names[i]); dev = &pci_dev->qdev; qdev_set_nic_properties(dev, nd); - - object_property_set_bool(OBJECT(dev), true, "realized", &err); - if (err) { - error_report_err(err); - object_unparent(OBJECT(dev)); - exit(1); - } + qdev_init_nofail(dev); return pci_dev; } -- 2.8.3