Re: [PATCH] arm64: PCI: free all allocated memory in case of failure
From: Timmy Li
Date: Mon May 22 2017 - 08:37:41 EST
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@xxxxxxxxxx>
>> ---
>> 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
>>
>>
>
> .
>