Commit 0c31f1d7 authored Dec 07, 2017 by Geert Uytterhoeven Committed by Bjorn Helgaas Dec 12, 2017

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: ddd535f1 ("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>

parent a19e2696

drivers/pci/host/pcie-rcar.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -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 @@ static int rcar_pcie_probe(struct platform_device *pdev)
		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;
		}