[PATCH 4.14 114/167] PCI: iproc: Fix NULL pointer dereference for BCMA

Greg Kroah-Hartman
2018-02-21T12:48:45Z

From: Ray Jui <ray.jui@broadcom.com>

commit 3b65ca50d24ce33cb92d88840e289135c92b40ed upstream.

With the inbound DMA mapping supported added, the iProc PCIe driver
parses DT property "dma-ranges" through call to
"of_pci_dma_range_parser_init()". In the case of BCMA, this results in a
NULL pointer deference due to a missing of_node.

Fix this by adding a guard in pcie-iproc-platform.c to only enable the
inbound DMA mapping logic when DT property "dma-ranges" is present.

Fixes: dd9d4e7498de3 ("PCI: iproc: Add inbound DMA mapping support")
Reported-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Ray Jui <ray.jui@broadcom.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Rafał Miłecki <rafal@milecki.pl>
cc: <stable@vger.kernel.org> # 4.10+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/pci/host/pcie-iproc-platform.c | 7 +++++++
drivers/pci/host/pcie-iproc.c | 8 +++++---
drivers/pci/host/pcie-iproc.h | 2 ++
3 files changed, 14 insertions(+), 3 deletions(-)

--- a/drivers/pci/host/pcie-iproc-platform.c
+++ b/drivers/pci/host/pcie-iproc-platform.c
@@ -92,6 +92,13 @@ static int iproc_pcie_pltfm_probe(struct
pcie->need_ob_cfg = true;
}

+ /*
+ * DT nodes are not used by all platforms that use the iProc PCIe
+ * core driver. For platforms that require explict inbound mapping
+ * configuration, "dma-ranges" would have been present in DT
+ */
+ pcie->need_ib_cfg = of_property_read_bool(np, "dma-ranges");
+
/* PHY use is optional */
pcie->phy = devm_phy_get(dev, "pcie-phy");
if (IS_ERR(pcie->phy)) {
--- a/drivers/pci/host/pcie-iproc.c
+++ b/drivers/pci/host/pcie-iproc.c
@@ -1396,9 +1396,11 @@ int iproc_pcie_setup(struct iproc_pcie *
}
}

- ret = iproc_pcie_map_dma_ranges(pcie);
- if (ret && ret != -ENOENT)
- goto err_power_off_phy;
+ if (pcie->need_ib_cfg) {
+ ret = iproc_pcie_map_dma_ranges(pcie);
+ if (ret && ret != -ENOENT)
+ goto err_power_off_phy;
+ }

#ifdef CONFIG_ARM
pcie->sysdata.private_data = pcie;
--- a/drivers/pci/host/pcie-iproc.h
+++ b/drivers/pci/host/pcie-iproc.h
@@ -74,6 +74,7 @@ struct iproc_msi;
* @ob: outbound mapping related parameters
* @ob_map: outbound mapping related parameters specific to the controller
*
+ * @need_ib_cfg: indicates SW needs to configure the inbound mapping window
* @ib: inbound mapping related parameters
* @ib_map: outbound mapping region related parameters
*
@@ -101,6 +102,7 @@ struct iproc_pcie {
struct iproc_pcie_ob ob;
const struct iproc_pcie_ob_map *ob_map;

+ bool need_ib_cfg;
struct iproc_pcie_ib ib;
const struct iproc_pcie_ib_map *ib_map;