[PATCH] arm64: PCI: free all allocated memory in case of failure

[PATCH] arm64: PCI: free all allocated memory in case of failure

[Timmy Li]

There are some memory allocations in pci_acpi_scan_root(). But
ri, root_ops and ri->cfg are not freed properly in failure cases,
which results in memory leaks. This patch fixes the potential
memory leaks.

Signed-off-by: Timmy Li <lixiaoping3@huawei.com>
---
 arch/arm64/kernel/pci.c | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index 4f0e3eb..e7e88ce 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -188,25 +188,22 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 
 	ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
 	if (!ri)
-		return NULL;
+		goto err_allocri;
 
 	root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
 	if (!root_ops)
-		return NULL;
+		goto err_allocops;
 
 	ri->cfg = pci_acpi_setup_ecam_mapping(root);
-	if (!ri->cfg) {
-		kfree(ri);
-		kfree(root_ops);
-		return NULL;
-	}
+	if (!ri->cfg)
+		goto err_ecam;
 
 	root_ops->release_info = pci_acpi_generic_release_info;
 	root_ops->prepare_resources = pci_acpi_root_prepare_resources;
 	root_ops->pci_ops = &ri->cfg->ops->pci_ops;
 	bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
 	if (!bus)
-		return NULL;
+		goto err_rootcreate;
 
 	pci_bus_size_bridges(bus);
 	pci_bus_assign_resources(bus);
@@ -215,6 +212,15 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
 		pcie_bus_configure_settings(child);
 
 	return bus;
+
+err_rootcreate:
+	pci_ecam_free(ri->cfg);
+err_ecam:
+	kfree(root_ops);
+err_allocops:
+	kfree(ri);
+err_allocri:
+	return NULL;
 }
 
 void pcibios_add_bus(struct pci_bus *bus)
-- 
1.9.1

Re: [PATCH] arm64: PCI: free all allocated memory in case of failure

[Lorenzo Pieralisi]

On Fri, May 12, 2017 at 05:57:47PM +0800, Timmy Li wrote:
> There are some memory allocations in pci_acpi_scan_root(). But
> ri, root_ops and ri->cfg are not freed properly in failure cases,
> which results in memory leaks. This patch fixes the potential
> memory leaks.
> 
> Signed-off-by: Timmy Li <lixiaoping3@huawei.com>
> ---
>  arch/arm64/kernel/pci.c | 22 ++++++++++++++--------
>  1 file changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
> index 4f0e3eb..e7e88ce 100644
> --- a/arch/arm64/kernel/pci.c
> +++ b/arch/arm64/kernel/pci.c
> @@ -188,25 +188,22 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>  
>  	ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
>  	if (!ri)
> -		return NULL;
> +		goto err_allocri;
>  
>  	root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
>  	if (!root_ops)
> -		return NULL;
> +		goto err_allocops;
>  
>  	ri->cfg = pci_acpi_setup_ecam_mapping(root);
> -	if (!ri->cfg) {
> -		kfree(ri);
> -		kfree(root_ops);
> -		return NULL;
> -	}
> +	if (!ri->cfg)
> +		goto err_ecam;
>  
>  	root_ops->release_info = pci_acpi_generic_release_info;

You are missing this ^^^^^^^^^

>  	root_ops->prepare_resources = pci_acpi_root_prepare_resources;
>  	root_ops->pci_ops = &ri->cfg->ops->pci_ops;
>  	bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
>  	if (!bus)

And how it works if (bus == NULL) here.

Lorenzo

> -		return NULL;
> +		goto err_rootcreate;
>  
>  	pci_bus_size_bridges(bus);
>  	pci_bus_assign_resources(bus);
> @@ -215,6 +212,15 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>  		pcie_bus_configure_settings(child);
>  
>  	return bus;
> +
> +err_rootcreate:
> +	pci_ecam_free(ri->cfg);
> +err_ecam:
> +	kfree(root_ops);
> +err_allocops:
> +	kfree(ri);
> +err_allocri:
> +	return NULL;
>  }
>  
>  void pcibios_add_bus(struct pci_bus *bus)
> -- 
> 1.9.1
> 
> 

Re: [PATCH] arm64: PCI: free all allocated memory in case of failure

[Timmy Li]

Hi Lorenzo,

Thanks for your review and sorry for the late reply.

On 2017/5/12 18:28, Lorenzo Pieralisi wrote:
> On Fri, May 12, 2017 at 05:57:47PM +0800, Timmy Li wrote:
>> There are some memory allocations in pci_acpi_scan_root(). But
>> ri, root_ops and ri->cfg are not freed properly in failure cases,
>> which results in memory leaks. This patch fixes the potential
>> memory leaks.
>>
>> Signed-off-by: Timmy Li <lixiaoping3@huawei.com>
>> ---
>>  arch/arm64/kernel/pci.c | 22 ++++++++++++++--------
>>  1 file changed, 14 insertions(+), 8 deletions(-)
>>
>> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
>> index 4f0e3eb..e7e88ce 100644
>> --- a/arch/arm64/kernel/pci.c
>> +++ b/arch/arm64/kernel/pci.c
>> @@ -188,25 +188,22 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>>  
>>  	ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
>>  	if (!ri)
>> -		return NULL;
>> +		goto err_allocri;
>>  
>>  	root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
>>  	if (!root_ops)
>> -		return NULL;
>> +		goto err_allocops;

I think it is still needed to free ri here When ri is allocated successfully and root_ops is not. Considering this is the only remain place that need to fix, a simple way to do this would be:
if (!root_ops) {
+	kfree(ri);
	return NULL;
}

>>  
>>  	ri->cfg = pci_acpi_setup_ecam_mapping(root);
>> -	if (!ri->cfg) {
>> -		kfree(ri);
>> -		kfree(root_ops);
>> -		return NULL;
>> -	}
>> +	if (!ri->cfg)
>> +		goto err_ecam;
>>  
>>  	root_ops->release_info = pci_acpi_generic_release_info;
> 
> You are missing this ^^^^^^^^^
> 
>>  	root_ops->prepare_resources = pci_acpi_root_prepare_resources;
>>  	root_ops->pci_ops = &ri->cfg->ops->pci_ops;
>>  	bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
>>  	if (!bus)
> 
> And how it works if (bus == NULL) here.

You are correct. There is no need to do anything When acpi_pci_root_create() fails.

> 
> Lorenzo
> 
>> -		return NULL;
>> +		goto err_rootcreate;
>>  
>>  	pci_bus_size_bridges(bus);
>>  	pci_bus_assign_resources(bus);
>> @@ -215,6 +212,15 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
>>  		pcie_bus_configure_settings(child);
>>  
>>  	return bus;
>> +
>> +err_rootcreate:
>> +	pci_ecam_free(ri->cfg);
>> +err_ecam:
>> +	kfree(root_ops);
>> +err_allocops:
>> +	kfree(ri);
>> +err_allocri:
>> +	return NULL;
>>  }
>>  
>>  void pcibios_add_bus(struct pci_bus *bus)
>> -- 
>> 1.9.1
>>
>>
> 
> .
> 

Re: [PATCH] arm64: PCI: free all allocated memory in case of failure

[Lorenzo Pieralisi]

On Mon, May 22, 2017 at 08:32:09PM +0800, Timmy Li wrote:
> Hi Lorenzo,
> 
> Thanks for your review and sorry for the late reply.
> 
> On 2017/5/12 18:28, Lorenzo Pieralisi wrote:
> > On Fri, May 12, 2017 at 05:57:47PM +0800, Timmy Li wrote:
> >> There are some memory allocations in pci_acpi_scan_root(). But
> >> ri, root_ops and ri->cfg are not freed properly in failure cases,
> >> which results in memory leaks. This patch fixes the potential
> >> memory leaks.
> >>
> >> Signed-off-by: Timmy Li <lixiaoping3@huawei.com>
> >> ---
> >>  arch/arm64/kernel/pci.c | 22 ++++++++++++++--------
> >>  1 file changed, 14 insertions(+), 8 deletions(-)
> >>
> >> diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
> >> index 4f0e3eb..e7e88ce 100644
> >> --- a/arch/arm64/kernel/pci.c
> >> +++ b/arch/arm64/kernel/pci.c
> >> @@ -188,25 +188,22 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> >>  
> >>  	ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
> >>  	if (!ri)
> >> -		return NULL;
> >> +		goto err_allocri;
> >>  
> >>  	root_ops = kzalloc_node(sizeof(*root_ops), GFP_KERNEL, node);
> >>  	if (!root_ops)
> >> -		return NULL;
> >> +		goto err_allocops;
> 
> I think it is still needed to free ri here When ri is allocated
> successfully and root_ops is not. Considering this is the only remain
> place that need to fix, a simple way to do this would be:
> if (!root_ops) {
> +	kfree(ri);
> 	return NULL;
> }

Ok, I will send a fix for that, thanks.

Lorenzo

> 
> >>  
> >>  	ri->cfg = pci_acpi_setup_ecam_mapping(root);
> >> -	if (!ri->cfg) {
> >> -		kfree(ri);
> >> -		kfree(root_ops);
> >> -		return NULL;
> >> -	}
> >> +	if (!ri->cfg)
> >> +		goto err_ecam;
> >>  
> >>  	root_ops->release_info = pci_acpi_generic_release_info;
> > 
> > You are missing this ^^^^^^^^^
> > 
> >>  	root_ops->prepare_resources = pci_acpi_root_prepare_resources;
> >>  	root_ops->pci_ops = &ri->cfg->ops->pci_ops;
> >>  	bus = acpi_pci_root_create(root, root_ops, &ri->common, ri->cfg);
> >>  	if (!bus)
> > 
> > And how it works if (bus == NULL) here.
> 
> You are correct. There is no need to do anything When acpi_pci_root_create() fails.
> 
> > 
> > Lorenzo
> > 
> >> -		return NULL;
> >> +		goto err_rootcreate;
> >>  
> >>  	pci_bus_size_bridges(bus);
> >>  	pci_bus_assign_resources(bus);
> >> @@ -215,6 +212,15 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> >>  		pcie_bus_configure_settings(child);
> >>  
> >>  	return bus;
> >> +
> >> +err_rootcreate:
> >> +	pci_ecam_free(ri->cfg);
> >> +err_ecam:
> >> +	kfree(root_ops);
> >> +err_allocops:
> >> +	kfree(ri);
> >> +err_allocri:
> >> +	return NULL;
> >>  }
> >>  
> >>  void pcibios_add_bus(struct pci_bus *bus)
> >> -- 
> >> 1.9.1
> >>
> >>
> > 
> > .
> > 
>