[PATCH] PCI: dwc: keystone: Fix potential NULL dereference

[Aleksandr Mishin]

In ks_pcie_setup_rc_app_regs() resource_list_first_type() may return
NULL which is later dereferenced. Fix this bug by adding NULL check.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 0f71c60ffd26 ("PCI: dwc: Remove storing of PCI resources")
Signed-off-by: Aleksandr Mishin <amishin@xxxxxxxxxx>
---
 drivers/pci/controller/dwc/pci-keystone.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
index 844de4418724..00d616654171 100644
--- a/drivers/pci/controller/dwc/pci-keystone.c
+++ b/drivers/pci/controller/dwc/pci-keystone.c
@@ -392,7 +392,11 @@ static void ks_pcie_setup_rc_app_regs(struct keystone_pcie *ks_pcie)
 	struct resource *mem;
 	int i;
 
-	mem = resource_list_first_type(&pp->bridge->windows, IORESOURCE_MEM)->res;
+	struct resource_entry *ft = resource_list_first_type(&pp->bridge->windows, IORESOURCE_MEM);
+	if (!ft)
+		return;
+
+	mem = ft->res;
 	start = mem->start;
 	end = mem->end;
 
-- 
2.30.2