PCI: rcar: Fix use-after-free in probe error path

If CONFIG_DEBUG_SLAB=y, and no PCIe card is inserted, the kernel crashes
during probe on r8a7791/koelsch:

  rcar-pcie fe000000.pcie: PCIe link down
  Unable to handle kernel paging request at virtual address 6b6b6b6b

(seeing this message requires earlycon and keep_bootcon).

Indeed, pci_free_host_bridge() frees the PCI host bridge, including the
embedded rcar_pcie object, so pci_free_resource_list() must not be called
afterwards.

To fix this, move the call to pci_free_resource_list() up, and update the
label name accordingly.

Fixes: ddd535f1ea3eb27e ("PCI: rcar: Fix memory leak when no PCIe card is inserted")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index 12796ec..52ab3cb 100644 (file)
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -1128,12 +1128,12 @@ static int rcar_pcie_probe(struct platform_device *pdev)
        err = rcar_pcie_get_resources(pcie);
        if (err < 0) {
                dev_err(dev, "failed to request resources: %d\n", err);
-               goto err_free_bridge;
+               goto err_free_resource_list;
        }
 
        err = rcar_pcie_parse_map_dma_ranges(pcie, dev->of_node);
        if (err)
-               goto err_free_bridge;
+               goto err_free_resource_list;
 
        pm_runtime_enable(dev);
        err = pm_runtime_get_sync(dev);
@@ -1176,9 +1176,9 @@ err_pm_put:
 err_pm_disable:
        pm_runtime_disable(dev);
 
-err_free_bridge:
-       pci_free_host_bridge(bridge);
+err_free_resource_list:
        pci_free_resource_list(&pcie->resources);
+       pci_free_host_bridge(bridge);
 
        return err;
 }