x86/PCI: fix memleak with get_current_resources()

In pci_scan_acpi_root(), when pci_use_crs is set, get_current_resources()
is used to get pci_root_info, and it will allocate name and resource array.

Later if pci_create_root_bus() can not create bus (could be already
there...) it will only free bus res list, but the name and res array is not
freed.

Let get_current_resource() take info pointer instead of using local info.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 30 insertions, 19 deletions

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index ed2835e148b5..a99b7d75f5ca 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -315,49 +315,55 @@ static void add_resources(struct pci_root_info *info)
         }
 }
 
+static void free_pci_root_info(struct pci_root_info *info)
+{
+        kfree(info->name);
+        kfree(info->res);
+        memset(info, 0, sizeof(struct pci_root_info));
+}
+
 static void
-get_current_resources(struct acpi_device *device, int busnum,
+get_current_resources(struct pci_root_info *info,
+                      struct acpi_device *device, int busnum,
                       int domain, struct list_head *resources)
 {
-        struct pci_root_info info;
         size_t size;
 
-        info.bridge = device;
-        info.res_num = 0;
-        info.resources = resources;
+        info->bridge = device;
+        info->res_num = 0;
+        info->resources = resources;
         acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_resource,
-                                &info);
-        if (!info.res_num)
+                                info);
+        if (!info->res_num)
                 return;
 
-        size = sizeof(*info.res) * info.res_num;
-        info.res = kmalloc(size, GFP_KERNEL);
-        if (!info.res)
+        size = sizeof(*info->res) * info->res_num;
+        info->res = kmalloc(size, GFP_KERNEL);
+        if (!info->res)
                 return;
 
-        info.name = kasprintf(GFP_KERNEL, "PCI Bus %04x:%02x", domain, busnum);
-        if (!info.name)
+        info->name = kasprintf(GFP_KERNEL, "PCI Bus %04x:%02x", domain, busnum);
+        if (!info->name)
                 goto name_alloc_fail;
 
-        info.res_num = 0;
+        info->res_num = 0;
         acpi_walk_resources(device->handle, METHOD_NAME__CRS, setup_resource,
-                                &info);
+                                info);
 
         if (pci_use_crs) {
-                add_resources(&info);
+                add_resources(info);
 
                 return;
         }
 
-        kfree(info.name);
-
 name_alloc_fail:
-        kfree(info.res);
+        free_pci_root_info(info);
 }
 
 struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
 {
         struct acpi_device *device = root->device;
+        struct pci_root_info info;
         int domain = root->segment;
         int busnum = root->secondary.start;
         LIST_HEAD(resources);
@@ -402,6 +408,7 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
 
         sd->domain = domain;
         sd->node = node;
+        memset(&info, 0, sizeof(struct pci_root_info));
         /*
          * Maybe the desired pci bus has been already scanned. In such case
          * it is unnecessary to scan the pci bus with the given domain,busnum.
@@ -415,7 +422,8 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
                 memcpy(bus->sysdata, sd, sizeof(*sd));
                 kfree(sd);
         } else {
-                get_current_resources(device, busnum, domain, &resources);
+                get_current_resources(&info, device, busnum, domain,
+                                        &resources);
 
                 /*
                  * _CRS with no apertures is normal, so only fall back to
@@ -429,6 +437,9 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
                         bus->subordinate = pci_scan_child_bus(bus);
                 else
                         pci_free_resource_list(&resources);
+
+                if (!bus && pci_use_crs)
+                        free_pci_root_info(&info);
         }
 
         /* After the PCI-E bus has been walked and all devices discovered,