PCI: rcar: Fix a potential NULL pointer dereference

In case __get_free_pages() fails and returns NULL, fix the return
value to -ENOMEM and release resources to avoid dereferencing a
NULL pointer.

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index a25527185bf1a316c9c293ed4e041d83933eeedb..0004b64571249dc54c3e3c55e8f31e19e2aaf7de 100644 (file)
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -929,6 +929,10 @@ static int rcar_pcie_enable_msi(struct rcar_pcie *pcie)
 
        /* setup MSI data target */
        msi->pages = __get_free_pages(GFP_KERNEL, 0);
+       if (!msi->pages) {
+               err = -ENOMEM;
+               goto err;
+       }
        base = virt_to_phys((void *)msi->pages);
 
        rcar_pci_write_reg(pcie, lower_32_bits(base) | MSIFE, PCIEMSIALR);