[PATCH] pci: pci-tegra: fix a potential NULL pointer dereference

[Kangjie Lu]

In case __get_free_pages fails and returns NULL, the fix returns
-ENOMEM and releases resources to avoid NULL pointer dereference.

Signed-off-by: Kangjie Lu <k...@umn.edu>
---
 drivers/pci/controller/pci-tegra.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/pci/controller/pci-tegra.c 
b/drivers/pci/controller/pci-tegra.c
index f4f53d092e00..0bdc6ee904f3 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c
@@ -1550,6 +1550,12 @@ static int tegra_pcie_msi_setup(struct tegra_pcie *pcie)
 
        /* setup AFI/FPCI range */
        msi->pages = __get_free_pages(GFP_KERNEL, 0);
+       if (!msi->pages) {
+               dev_err(dev, "failed to get free pages\n");
+               err = -ENOMEM;
+               goto err;
+       }
+
        msi->phys = virt_to_phys((void *)msi->pages);
        host->msi = &msi->chip;
 
-- 
2.17.1