RE: [PATCHv2 1/4] PCI: dwc: fix potential memory leak

[Z.q. Hou]

Hi Lorenzo,

> -----Original Message-----
> From: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Sent: 2018年12月5日 23:40
> To: Z.q. Hou <zhiqiang.hou@xxxxxxx>
> Cc: linux-pci@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> bhelgaas@xxxxxxxxxx; jingoohan1@xxxxxxxxx;
> gustavo.pimentel@xxxxxxxxxxxx; Roy Zang <roy.zang@xxxxxxx>; Mingkai Hu
> <mingkai.hu@xxxxxxx>; M.h. Lian <minghuan.lian@xxxxxxx>
> Subject: Re: [PATCHv2 1/4] PCI: dwc: fix potential memory leak
> 
> On Wed, Nov 07, 2018 at 10:09:04AM +0000, Z.q. Hou wrote:
> > From: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
> >
> > Free the allocated pci_host_bridge struct when failed to get host
> > bridge resources, and free the resource windows before free the
> > bridge.
> >
> > Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@xxxxxxx>
> > Acked-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
> > ---
> > V2:
> >  - Reworded the subject.
> >
> >  drivers/pci/controller/dwc/pcie-designware-host.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c
> > b/drivers/pci/controller/dwc/pcie-designware-host.c
> > index 29a05759a294..ecacce016489 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> > @@ -353,7 +353,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
> >  	ret = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff,
> >  					&bridge->windows, &pp->io_base);
> >  	if (ret)
> > -		return ret;
> > +		goto error;
> >
> >  	ret = devm_request_pci_bus_resources(dev, &bridge->windows);
> >  	if (ret)
> > @@ -502,6 +502,7 @@ int dw_pcie_host_init(struct pcie_port *pp)
> >  	return 0;
> >
> >  error:
> > +	pci_free_resource_list(&bridge->windows);
> 
> This would cause a double-free, devm_request_pci_bus_resource already
> takes care of freeing resources, patch dropped.

Yes, I just understood.

> Lorenzo
> 
> >  	pci_free_host_bridge(bridge);
> >  	return ret;
> >  }
> > --
> > 2.17.1
> >
Thanks,
Zhiqiang