Re: [Qemu-devel] [PATCH] hw/pci: use-after-free in pci_nic_init_nofail when nic device fails to initialize

[Jason Wang]

On 2017年01月09日 13:26, Alex Kompel wrote:
Looks like this line got wrapped: "@@ -1805,13 +1805,7 @@ PCIDevice
*pci_nic_init_nofail(NICInfo *nd, PCIBus *rootbus,"
Sorry about that. Could you unwrap it or use the attached text file?

Thanks,
-Alex

Ok, applied. But please use git format-patch and git send-email for 
future submission of patches.

Thanks


On Sun, Jan 8, 2017 at 8:06 PM, Jason Wang <jasow...@redhat.com> wrote:

On 2017年01月07日 07:48, Alex Kompel wrote:
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,

Hello, looks like the patch were corrupted possibly by your email client.
Please check, we usually send patch through git send-email.

Thanks


       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