[PATCH 4.4 31/84] PCI: xilinx: Check for __get_free_pages() failure

[Greg Kroah-Hartman]

[ Upstream commit 699ca30162686bf305cdf94861be02eb0cf9bda2 ]

If __get_free_pages() fails, return -ENOMEM to avoid a NULL pointer
dereference.

Signed-off-by: Kangjie Lu <k...@umn.edu>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
Reviewed-by: Steven Price <steven.pr...@arm.com>
Reviewed-by: Mukesh Ojha <mo...@codeaurora.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/pci/host/pcie-xilinx.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/host/pcie-xilinx.c b/drivers/pci/host/pcie-xilinx.c
index 4cfa46360d12..6a2499f4d610 100644
--- a/drivers/pci/host/pcie-xilinx.c
+++ b/drivers/pci/host/pcie-xilinx.c
@@ -349,14 +349,19 @@ static const struct irq_domain_ops msi_domain_ops = {
  * xilinx_pcie_enable_msi - Enable MSI support
  * @port: PCIe port information
  */
-static void xilinx_pcie_enable_msi(struct xilinx_pcie_port *port)
+static int xilinx_pcie_enable_msi(struct xilinx_pcie_port *port)
 {
        phys_addr_t msg_addr;
 
        port->msi_pages = __get_free_pages(GFP_KERNEL, 0);
+       if (!port->msi_pages)
+               return -ENOMEM;
+
        msg_addr = virt_to_phys((void *)port->msi_pages);
        pcie_write(port, 0x0, XILINX_PCIE_REG_MSIBASE1);
        pcie_write(port, msg_addr, XILINX_PCIE_REG_MSIBASE2);
+
+       return 0;
 }
 
 /* INTx Functions */
@@ -555,6 +560,7 @@ static int xilinx_pcie_init_irq_domain(struct 
xilinx_pcie_port *port)
        struct device *dev = port->dev;
        struct device_node *node = dev->of_node;
        struct device_node *pcie_intc_node;
+       int ret;
 
        /* Setup INTx */
        pcie_intc_node = of_get_next_child(node, NULL);
@@ -582,7 +588,9 @@ static int xilinx_pcie_init_irq_domain(struct 
xilinx_pcie_port *port)
                        return PTR_ERR(port->irq_domain);
                }
 
-               xilinx_pcie_enable_msi(port);
+               ret = xilinx_pcie_enable_msi(port);
+               if (ret)
+                       return ret;
        }
 
        return 0;
-- 
2.20.1