PCI: rcar-pcie: Fix memory leak when no PCIe card is inserted

Message ID 20170802090307.GA24167@red-moon
State Not Applicable
Headers show

Commit Message

Lorenzo Pieralisi Aug. 2, 2017, 9:03 a.m.
On Wed, Aug 02, 2017 at 04:13:20PM +0900, Harunobu Kurokawa wrote:
> When no PCIe card is inserted, there is a memory leak as
> pci_free_resource_list is not called before returning.
> 
> Signed-off-by: Harunobu Kurokawa <harunobu.kurokawa.dn@renesas.com>
> ---
>  drivers/pci/host/pcie-rcar.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
> index ac80fbb..9b06de6 100644
> --- a/drivers/pci/host/pcie-rcar.c
> +++ b/drivers/pci/host/pcie-rcar.c
> @@ -1190,14 +1190,15 @@ static int rcar_pcie_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> -err_free_bridge:
> -	pci_free_host_bridge(bridge);
> -
>  err_pm_put:
>  	pm_runtime_put(dev);
>  
>  err_pm_disable:
>  	pm_runtime_disable(dev);
> +
> +err_free_bridge:
> +	pci_free_host_bridge(bridge);
> +	pci_free_resource_list(&pcie->resources);
>  	return err;
>  }

The error code path needs fixing but not like this (with a single
patch lumping all fixes - well, actually it does not - together).

Step one, patch below. Step two free the &pci->resources list
(which IIUC was not freed even before commit 90634e854079) in
a separate patch.

Am I missing something ?

Please apply, check and repost the patch if it is ok, thanks.

-- >8 --
Subject: [PATCH] PCI: rcar: Fix error exit path

Commit 90634e854079 ("PCI: rcar: Convert PCI scan API to
pci_scan_root_bus_bridge()") converted PCI root bus scan API
to the new pci_scan_root_bus_bridge() API; in the process
some error paths were not updated correctly which may
cause memory leaks.

Fix the driver error exit path reinstating the previous
correct error exit behaviour.

Fixes: 90634e854079 ("PCI: rcar: Convert PCI scan API to pci_scan_root_bus_bridge()")
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 drivers/pci/host/pcie-rcar.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

Comments

Harunobu Kurokawa Aug. 3, 2017, 5:07 a.m. | #1
Hi 

> -----Original Message-----
> From: Lorenzo Pieralisi [mailto:lorenzo.pieralisi@arm.com]
> Sent: Wednesday, August 2, 2017 6:03 PM
> To: HARUNOBU KUROKAWA <harunobu.kurokawa.dn@renesas.com>
> Cc: horms@verge.net.au; bhelgaas@google.com; linux-pci@vger.kernel.org; linux-renesas-soc@vger.kernel.org;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH] PCI: rcar-pcie: Fix memory leak when no PCIe card is inserted
> 
> On Wed, Aug 02, 2017 at 04:13:20PM +0900, Harunobu Kurokawa wrote:
> > When no PCIe card is inserted, there is a memory leak as
> > pci_free_resource_list is not called before returning.
> >
> > Signed-off-by: Harunobu Kurokawa <harunobu.kurokawa.dn@renesas.com>
> > ---
> >  drivers/pci/host/pcie-rcar.c | 7 ++++---
> >  1 file changed, 4 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/host/pcie-rcar.c
> > b/drivers/pci/host/pcie-rcar.c index ac80fbb..9b06de6 100644
> > --- a/drivers/pci/host/pcie-rcar.c
> > +++ b/drivers/pci/host/pcie-rcar.c
> > @@ -1190,14 +1190,15 @@ static int rcar_pcie_probe(struct
> > platform_device *pdev)
> >
> >  	return 0;
> >
> > -err_free_bridge:
> > -	pci_free_host_bridge(bridge);
> > -
> >  err_pm_put:
> >  	pm_runtime_put(dev);
> >
> >  err_pm_disable:
> >  	pm_runtime_disable(dev);
> > +
> > +err_free_bridge:
> > +	pci_free_host_bridge(bridge);
> > +	pci_free_resource_list(&pcie->resources);
> >  	return err;
> >  }
> 
> The error code path needs fixing but not like this (with a single patch lumping all fixes - well, actually it does not - together).
> 
> Step one, patch below. Step two free the &pci->resources list (which IIUC was not freed even before commit 90634e854079) in a separate
> patch.
> 
> Am I missing something ?
> 
> Please apply, check and repost the patch if it is ok, thanks.
Yes, I'll sprit the patch and repost them.

Best regards,
Kurokawa.


> 
> -- >8 --
> Subject: [PATCH] PCI: rcar: Fix error exit path
> 
> Commit 90634e854079 ("PCI: rcar: Convert PCI scan API to
> pci_scan_root_bus_bridge()") converted PCI root bus scan API to the new pci_scan_root_bus_bridge() API; in the process some error
> paths were not updated correctly which may cause memory leaks.
> 
> Fix the driver error exit path reinstating the previous correct error exit behaviour.
> 
> Fixes: 90634e854079 ("PCI: rcar: Convert PCI scan API to pci_scan_root_bus_bridge()")
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> ---
>  drivers/pci/host/pcie-rcar.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c index 246d485..007523e 100644
> --- a/drivers/pci/host/pcie-rcar.c
> +++ b/drivers/pci/host/pcie-rcar.c
> @@ -471,10 +471,8 @@ static int rcar_pcie_enable(struct rcar_pcie *pcie)
>  		bridge->msi = &pcie->msi.chip;
> 
>  	ret = pci_scan_root_bus_bridge(bridge);
> -	if (ret < 0) {
> -		kfree(bridge);
> +	if (ret < 0)
>  		return ret;
> -	}
> 
>  	bus = bridge->bus;
> 
> @@ -1190,14 +1188,15 @@ static int rcar_pcie_probe(struct platform_device *pdev)
> 
>  	return 0;
> 
> -err_free_bridge:
> -	pci_free_host_bridge(bridge);
> -
>  err_pm_put:
>  	pm_runtime_put(dev);
> 
>  err_pm_disable:
>  	pm_runtime_disable(dev);
> +
> +err_free_bridge:
> +	pci_free_host_bridge(bridge);
> +
>  	return err;
>  }
> 
> --
> 2.10.0

Patch

diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index 246d485..007523e 100644
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -471,10 +471,8 @@  static int rcar_pcie_enable(struct rcar_pcie *pcie)
 		bridge->msi = &pcie->msi.chip;
 
 	ret = pci_scan_root_bus_bridge(bridge);
-	if (ret < 0) {
-		kfree(bridge);
+	if (ret < 0)
 		return ret;
-	}
 
 	bus = bridge->bus;
 
@@ -1190,14 +1188,15 @@  static int rcar_pcie_probe(struct platform_device *pdev)
 
 	return 0;
 
-err_free_bridge:
-	pci_free_host_bridge(bridge);
-
 err_pm_put:
 	pm_runtime_put(dev);
 
 err_pm_disable:
 	pm_runtime_disable(dev);
+
+err_free_bridge:
+	pci_free_host_bridge(bridge);
+
 	return err;
 }