[PATCH 5.1 125/155] PCI: rcar: Fix a potential NULL pointer dereference

Greg Kroah-Hartman
2019-06-13T15:56:45Z

[ 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>
---
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 6a4e435bd35f..765c39911c0c 100644
--- a/drivers/pci/controller/pcie-rcar.c
+++ b/drivers/pci/controller/pcie-rcar.c
@@ -931,6 +931,10 @@ 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);
--
2.20.1