[PATCH v2] pci: pcie-rcar: 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 <kjlu@xxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

---
V2 removes the error message.
---
 drivers/pci/controller/pcie-rcar.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
index c8febb009454..71e55995c058 100644
--- 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, base | MSIFE, PCIEMSIALR);
-- 
2.17.1