PCI: rcar: Fix a potential NULL pointer dereference

[ Upstream commit f0d14edd2ba43b995bef4dd5da5ffe0ae19321a1 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index 41edce16a07cdcebd9df7f6ef466d9f28babb545..fad57d068db373357eafd617527892724254208f 100644 (file)
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -888,6 +888,10 @@ 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);