[PATCH RFC] PCI: kirin: prevent buffer overflow in kirin_pcie_parse_port

[Anastasia Belova]

If pcie->num_slots = MAX_PCI_SLOTS, i equals MAX_PCI_SLOTS
during the next iteration. Then pcie->gpio_id_reset is accessed
by invalid index. Strengthen check on pcie->num_slots to
prevent this.

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

Fixes: b22dbbb24571 ("PCI: kirin: Support PERST# GPIOs for HiKey970 external PEX 8606 bridge")
Signed-off-by: Anastasia Belova <abelova@xxxxxxxxxxxxx>
---
 drivers/pci/controller/dwc/pcie-kirin.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-kirin.c b/drivers/pci/controller/dwc/pcie-kirin.c
index d5523f302102..5ef3384c137d 100644
--- a/drivers/pci/controller/dwc/pcie-kirin.c
+++ b/drivers/pci/controller/dwc/pcie-kirin.c
@@ -413,7 +413,7 @@ static int kirin_pcie_parse_port(struct kirin_pcie *pcie,
 				continue;
 
 			pcie->num_slots++;
-			if (pcie->num_slots > MAX_PCI_SLOTS) {
+			if (pcie->num_slots >= MAX_PCI_SLOTS) {
 				dev_err(dev, "Too many PCI slots!\n");
 				ret = -EINVAL;
 				goto put_node;
-- 
2.30.2