On Wed, Jan 29, 2014 at 5:23 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote:
> On Wed, Jan 29, 2014 at 3:12 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote:
>> On Wed, Jan 15, 2014 at 12:11:19AM +0100, Djalal Harouni wrote:
>>> On error paths make sure that the pci_host_bridge struct is freed.
>>>
>>> Signed-off-by: Djalal Harouni <tixxdz@xxxxxxxxxx>
>>
>> Applied to pci/misc, thanks!
>>
>>> ---
>>> On top of linux-next.
>>>
>>> drivers/pci/probe.c | 10 +++++-----
>>> 1 file changed, 5 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
>>> index 23cdfac..483566c 100644
>>> --- a/drivers/pci/probe.c
>>> +++ b/drivers/pci/probe.c
>>> @@ -1771,15 +1771,13 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
>>> bridge->dev.release = pci_release_host_bridge_dev;
>>> dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(b), bus);
>>> error = pcibios_root_bridge_prepare(bridge);
>>> - if (error) {
>>> - kfree(bridge);
>>> - goto err_out;
>>> - }
>>> + if (error)
>>> + goto host_bridge_err;
>>>
>>> error = device_register(&bridge->dev);
>>> if (error) {
>>> put_device(&bridge->dev);
>>> - goto err_out;
>>> + goto host_bridge_err;
>>> }
>>> b->bridge = get_device(&bridge->dev);
>>> device_enable_async_suspend(b->bridge);
>>> @@ -1836,6 +1834,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
>>> class_dev_reg_err:
>>> put_device(&bridge->dev);
>>> device_unregister(&bridge->dev);
>>> +host_bridge_err:
>>> + kfree(bridge);
>>> err_out:
>>> kfree(b);
>>> return NULL;
>>> --
>
> Are you joking?
>
> NAK.
>
> even device_register fail,it will have one ref hold, and
> put_device(&bridge->dev)
> it will trigger bridge->dev.release aka pci_release_host_bridge_dev;
> that function will free the bridge.
> You will have double free.
OK, dropped, thanks. I wasn't joking, I just made a mistake.
> commit 343df771e671d821478dd3ef525a0610b808dbf8
> Author: Jiang Liu <liuj97@xxxxxxxxx>
> Date: Fri Jun 7 01:10:08 2013 +0800
>
> PCI: Fix refcount issue in pci_create_root_bus() error recovery path
>
> After calling device_register(&bridge->dev), the bridge is reference-
> counted, and it is illegal to call kfree() on it except in the release
> function.
>
> [bhelgaas: changelog, use put_device() after device_register() failure]
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
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